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Hi! We cleaned up your code for you!#14

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Hi! We cleaned up your code for you!#14
GunioRobot wants to merge 1 commit intogit:masterfrom
GunioRobot:clean

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@GunioRobot
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@GunioRobot GunioRobot commented Oct 21, 2011

Hi there!

This is WhitespaceBot from Gun.io. I'm an open-source robot that removes trailing white space in your code, and gives you a gitignore file if you didn't have one! I've only cleaned your most popular project, and I've added you to a list of users not to contact again, so you won't get any more pull requests from me unless you ask. If I'm misbehaving, please email my owner and tell him to turn me off!

== About Gun.io ==
Gun.io is a place for hackers to hire each other for small tasks. We offer no-hassle, winner-take-all freelance gigs, by hackers, for hackers. Got a bug you can't fix or a feature you want for your project? Post a gig and have somebody else sort it out for you. Oh, and it's free for open source! Sign up and get notified about new gigs you can work on!

== About WhitespaceBot==
WhitespaceBot is a simple open source robot which uses GitHub's API as a way of cleaning up open source projects! We've put up a paid bounty for whoever can add security fixing features to it.

@gitster
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gitster commented Oct 21, 2011

Almost all of these are intentional and updating the test vector without changing the matching test would break. Don't throw random crap like this without testing.

Besides, development of Git itself does not happen via Github pull requests.

Closing this, and blocking the troll robot.

@gitster gitster closed this Oct 21, 2011
@cowlicks
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cowlicks commented Oct 21, 2011

'like'

asmeurer pushed a commit to asmeurer/git that referenced this pull request Jan 9, 2012
@gitster
What's cooking (2011/05 git#14)
c865b92
pclouds referenced this pull request in TortoiseGit/tgit Jan 13, 2012
@pclouds @gitster
t1510: setup case #14
69bf2b1 
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
kusma pushed a commit to kusma/git that referenced this pull request May 31, 2012
@dscho
Windows resource: handle dashes in the Git version gracefully
e6ada76 
Reported by postiffm as issue git#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
aroben referenced this pull request in aroben/git Jun 15, 2012
@dscho
Windows resource: handle dashes in the Git version gracefully
4c58927 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
kusma pushed a commit to kusma/git that referenced this pull request Jun 24, 2012
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
9e9b332 
Reported by postiffm as issue git#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
kblees referenced this pull request in kblees/git Oct 24, 2012
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
1c7bf99 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
kblees referenced this pull request in kblees/git Oct 24, 2012
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
9530c48 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
frogonwheels referenced this pull request in frogonwheels/git Dec 23, 2012
@dscho
Windows resource: handle dashes in the Git version gracefully
2440926 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
frogonwheels referenced this pull request in frogonwheels/git Feb 5, 2013
@dscho @kusma
Windows resource: handle dashes in the Git version gracefully
9b38bdd 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
frogonwheels referenced this pull request in frogonwheels/git Feb 5, 2013
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
7e34dd2 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
frogonwheels referenced this pull request in frogonwheels/git Feb 5, 2013
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
eb1efa3 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
gitster pushed a commit that referenced this pull request Jun 7, 2013
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
2be50ea 
Reported by postiffm as issue #14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
kblees referenced this pull request in kblees/git Jun 9, 2013
@dscho @patthoyts
Windows resource: handle dashes in the Git version gracefully
67ed845 
Reported by postiffm as issue msysgit#14.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
gitster pushed a commit that referenced this pull request Jul 9, 2018
@newren @gitster
merge-recursive: enforce rule that index matches head before merging
9cae566 
builtin/merge.c says that when we are about to perform a merge:

    ...the index must be in sync with the head commit.  The strategies are
    responsible to ensure this.

merge-recursive has always relied on unpack_trees() to enforce this
requirement, except in the case of an "Already up to date!" merge.
unpack-trees.c does not actually enforce this requirement, though.  It
allows for a pair of exceptions, in cases which it refers to as #14(ALT)
and #2ALT.  Documentation/technical/trivial-merge.txt can be consulted for
the precise meanings of the various case numbers and their meanings for
unpack-trees.c, but we have a high-level description of the intent behind
these two exceptions in a combined and summarized form in
Documentation/git-merge.txt:

    ...[merge will] abort if there are any changes registered in the index
    relative to the `HEAD` commit.  (One exception is when the changed index
    entries are in the state that would result from the merge already.)

While this high-level description does describe conditions under which it
would be safe to allow the index to diverge from HEAD, it does not match
what is actually implemented.  In particular, unpack-trees.c has no
knowledge of renames, and these two exceptions were written assuming that
no renames take place.  Once renames get into the mix, it is no longer
safe to allow the index to not match for #2ALT.  We could modify
unpack-trees to only allow #14(ALT) as an exception, but that would be
more strict than required for the resolve strategy (since the resolve
strategy doesn't handle renames at all).  Therefore, unpack_trees.c seems
like the wrong place to fix this.

Further, if someone fixes the combination of break and rename detection
and modifies merge-recursive to take advantage of the combination, then it
will also no longer be safe to allow the index to not match for #14(ALT)
when the recursive strategy is in use.  Therefore, leaving one of the
exceptions in place with the recursive merge strategy feels like we are
just leaving a latent bug in the code for folks in the future to stumble
across.

It may be possible to fix both unpack-trees and merge-recursive in a way
that implements the exception as stated in Documentation/git-merge.txt,
but it would be somewhat complex, possibly also buggy at first, and
ultimately, not all that valuable.  Instead, just enforce the requirement
stated in builtin/merge.c; error out if the index does not match the HEAD
commit, just like the 'ours' and 'octopus' strategies do.

Some testcase fixups were in order:
  t7611: had many tests designed to show that `git merge --abort` could
	 not always restore the index and working tree to the state they
	 were in before the merge started.  The tests that were associated
	 with having changes in the index before the merge started are no
         longer applicable, so they have been removed.
  t7504: had a few tests that had stray staged changes that were not
         actually part of the test under consideration
  t6044: We no longer expect stray staged changes to sometimes result
         in the merge continuing.  Also, fix a case where a merge
         didn't abort but should have.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
gitster pushed a commit that referenced this pull request Jul 11, 2018
@newren @gitster
merge-recursive: enforce rule that index matches head before merging
eddd1a4 
builtin/merge.c says that when we are about to perform a merge:

    ...the index must be in sync with the head commit.  The strategies are
    responsible to ensure this.

merge-recursive has always relied on unpack_trees() to enforce this
requirement, except in the case of an "Already up to date!" merge.
unpack-trees.c does not actually enforce this requirement, though.  It
allows for a pair of exceptions, in cases which it refers to as #14(ALT)
and #2ALT.  Documentation/technical/trivial-merge.txt can be consulted for
the precise meanings of the various case numbers and their meanings for
unpack-trees.c, but we have a high-level description of the intent behind
these two exceptions in a combined and summarized form in
Documentation/git-merge.txt:

    ...[merge will] abort if there are any changes registered in the index
    relative to the `HEAD` commit.  (One exception is when the changed index
    entries are in the state that would result from the merge already.)

While this high-level description does describe conditions under which it
would be safe to allow the index to diverge from HEAD, it does not match
what is actually implemented.  In particular, unpack-trees.c has no
knowledge of renames, and these two exceptions were written assuming that
no renames take place.  Once renames get into the mix, it is no longer
safe to allow the index to not match for #2ALT.  We could modify
unpack-trees to only allow #14(ALT) as an exception, but that would be
more strict than required for the resolve strategy (since the resolve
strategy doesn't handle renames at all).  Therefore, unpack_trees.c seems
like the wrong place to fix this.

Further, if someone fixes the combination of break and rename detection
and modifies merge-recursive to take advantage of the combination, then it
will also no longer be safe to allow the index to not match for #14(ALT)
when the recursive strategy is in use.  Therefore, leaving one of the
exceptions in place with the recursive merge strategy feels like we are
just leaving a latent bug in the code for folks in the future to stumble
across.

It may be possible to fix both unpack-trees and merge-recursive in a way
that implements the exception as stated in Documentation/git-merge.txt,
but it would be somewhat complex, possibly also buggy at first, and
ultimately, not all that valuable.  Instead, just enforce the requirement
stated in builtin/merge.c; error out if the index does not match the HEAD
commit, just like the 'ours' and 'octopus' strategies do.

Some testcase fixups were in order:
  t7611: had many tests designed to show that `git merge --abort` could
	 not always restore the index and working tree to the state they
	 were in before the merge started.  The tests that were associated
	 with having changes in the index before the merge started are no
         longer applicable, so they have been removed.
  t7504: had a few tests that had stray staged changes that were not
         actually part of the test under consideration
  t6044: We no longer expect stray staged changes to sometimes result
         in the merge continuing.  Also, fix a case where a merge
         didn't abort but should have.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 5, 2021
@ahunt
init_db(): fix leak by removing git_init_db_config()
a91ef5b 
init_db_config_path could be leaked because:
1. git_init_db_config() allocates new data into init_db_config_path on every
   invocation without freeing preexisting data.
2. git_init_db_config() can be called multiple times for a single git_config()
   invocation (see docs on git_config() for context).
Furthermore, until very recently, git_config(git_init_db_config(), ...) could
have been invoked twice in a single process as git_init_db_config() used to
be used to handle core.* config settings. This was changed in a previous
patch in this series.

Freeing the existing value in git_init_db_config() would be the least intrusive
fix, however switching to git_config_get_value() simplifies the code further by
letting us remove the static pointer (furthermore, the returned data is owned by
the config cache, saving us from having to worry about freeing it later).

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
4198283 
Most of these pointers can safely be freed when cmd_clone() completes, therefore
we make sure to free them. The one exception is that we UNLEAK(repo) because
repo can point either to argv[0], or a malloc'd string returned by
absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): path is unconditionally
overwritten later (with a different path), triggering a leak of the original
contents. Hence we need to free it: freeing immediately after use (but only in
the case where it contains data) seems like the cleanest solution, as opposed to
freeing it unconditionally before path is reused for another path. This leak
appears to have been introduced in:
f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt of the
LSAN output below (the full list is omitted because it's far too long, and mostly
consists of indirect leakage of members of the refs we are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
vv    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
init: fix leak by removing git_init_db_config()
4c85da6 
init_db_config_path could be leaked because:
1. git_init_db_config() allocates new data into init_db_config_path on every
   invocation without freeing preexisting data.
2. git_init_db_config() can be called multiple times for a single git_config()
   invocation (see docs on git_config() for context).
Furthermore, until very recently, git_config(git_init_db_config(), ...) could
have been invoked twice in a single process as git_init_db_config() used to
be used to handle core.* config settings. This was changed in a previous
patch in this series - that change alone might fix the leak in some scenarios,
but is not enough to guarantee that we never leak.

Freeing the existing value in git_init_db_config() would be the least intrusive
fix, however switching to git_config_get_value() simplifies the code further by
letting us remove the static pointer (furthermore, the returned data is owned by
the config cache, saving us from having to worry about freeing it later).

The following commit is when we first started using git_init_db_config() for 2
different purposes:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11)
Although I suspect the potential for a leak existed since the original
implementation in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
init: fix leak by removing git_init_db_config()
61e66db 
init_db_config_path could be leaked because:
1. git_init_db_config() allocates new data into init_db_config_path on every
   invocation without freeing preexisting data.
2. git_init_db_config() can be called multiple times for a single git_config()
   invocation (see docs on git_config() for context).
Furthermore, until very recently, git_config(git_init_db_config(), ...) could
have been invoked twice in a single process as git_init_db_config() used to
be used to handle core.* config settings. This was changed in a previous
patch in this series - that change alone might fix the leak in some scenarios,
but is not enough to guarantee that we never leak.

Freeing the existing value in git_init_db_config() would be the least intrusive
fix, however switching to git_config_get_value() simplifies the code further by
letting us remove the static pointer (furthermore, the returned data is owned by
the config cache, saving us from having to worry about freeing it later).

The following commit is when we first started using git_init_db_config() for 2
different purposes:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11)
Although I suspect the potential for a leak existed since the original
implementation in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
init: fix leak by removing git_init_db_config()
8f61cd7 
Also UNLEAK template_dir in cmd_init_db(), as we are passing it into init_db()
and cannot easily free it without making more intrusive changes to execution
flow.

init_db_config_path could be leaked because:
1. git_init_db_config() allocates new data into init_db_config_path on every
   invocation without freeing preexisting data.
2. git_init_db_config() can be called multiple times for a single git_config()
   invocation (see docs on git_config() for context).
Furthermore, until very recently, git_config(git_init_db_config(), ...) could
have been invoked twice in a single process as git_init_db_config() used to
be used to handle core.* config settings. This was changed in a previous
patch in this series - that change alone might fix the leak in some scenarios,
but is not enough to guarantee that we never leak.

Freeing the existing value in git_init_db_config() would be the least intrusive
fix, however switching to git_config_get_value() simplifies the code further by
letting us remove the static pointer (furthermore, the returned data is owned by
the config cache, saving us from having to worry about freeing it later).

The following commit is when we first started using git_init_db_config() for 2
different purposes:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11)
Although I suspect the potential for a leak existed since the original
implementation in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
5196966 
Most of these pointers can safely be freed when cmd_clone() completes, therefore
we make sure to free them. The one exception is that we UNLEAK(repo) because
repo can point either to argv[0], or a malloc'd string returned by
absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): path is unconditionally
overwritten later (with a different path), triggering a leak of the original
contents. Hence we need to free it: freeing immediately after use (but only in
the case where it contains data) seems like the cleanest solution, as opposed to
freeing it unconditionally before path is reused for another path. This leak
appears to have been introduced in:
f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt of the
LSAN output below (the full list is omitted because it's far too long, and mostly
consists of indirect leakage of members of the refs we are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
vv    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 6, 2021
@ahunt
init: fix leak by removing git_init_db_config()
7d80a01 
Also UNLEAK template_dir in cmd_init_db(), as we are passing it into init_db()
and cannot easily free it without making more intrusive changes to execution
flow.

init_db_config_path could be leaked because:
1. git_init_db_config() allocates new data into init_db_config_path on every
   invocation without freeing preexisting data.
2. git_init_db_config() can be called multiple times for a single git_config()
   invocation (see docs on git_config() for context).
Furthermore, until very recently, git_config(git_init_db_config(), ...) could
have been invoked twice in a single process as git_init_db_config() used to
be used to handle core.* config settings. This was changed in a previous
patch in this series - that change alone might fix the leak in some scenarios,
but is not enough to guarantee that we never leak.

Freeing the existing value in git_init_db_config() would be the least intrusive
fix, however switching to git_config_get_value() simplifies the code further by
letting us remove the static pointer (furthermore, the returned data is owned by
the config cache, saving us from having to worry about freeing it later).

The following commit is when we first started using git_init_db_config() for 2
different purposes:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11)
Although I suspect the potential for a leak existed since the original
implementation in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
f12d70b 
The primary goal of this change is to stop leaking init_db_template_dir. This
leak can happen because:
1. git_init_db_config() allocates new memory into init_db_template_dir without
   first freeing.
2. init_db_template_dir might already contain data, either because:
 2.1 git_config() can be invoked twice with this callback in a single process -
     at least 2 allocations are likely.
 2.2 A single git_config() allocation can invoke the callback multiple times for
     a given key (see further explanation in the function docs) - each of those
     calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir) before
overwriting it. Instead we convert to git_config_get_value() as that is more
explicit, seemingly more efficient, AND avoids allocations (the returned result
is owned by the config cache, so we aren't responsible for freeing it).

By removing init_db_template_dir, git_init_db_config() ends up only being
responsible for forwarding core.* config values to platform_core_config().
However platform_core_config() already ignores non-core.* config values,
so we can safely remove git_init_db_config() and invoke git_config() directly on
platform_core_config().

In addition to those changes, we squash another leak by UNLEAK'ing template_dir
in cmd_init_db(). We are already passing it into init_db() and cannot easily
free it without making more intrusive changes to execution flow.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
I suspect the potential for a leak existed since the original implementation of
git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
f2cb7d6 
The primary goal of this change is to stop leaking init_db_template_dir. This
leak can happen because:
1. git_init_db_config() allocates new memory into init_db_template_dir without
   first freeing.
2. init_db_template_dir might already contain data, either because:
 2.1 git_config() can be invoked twice with this callback in a single process -
     at least 2 allocations are likely.
 2.2 A single git_config() allocation can invoke the callback multiple times for
     a given key (see further explanation in the function docs) - each of those
     calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir) before
overwriting it. Instead we convert to git_config_get_value() as that is more
explicit, seemingly more efficient, AND avoids allocations (the returned result
is owned by the config cache, so we aren't responsible for freeing it).

By removing init_db_template_dir, git_init_db_config() ends up only being
responsible for forwarding core.* config values to platform_core_config().
However platform_core_config() already ignores non-core.* config values,
so we can safely remove git_init_db_config() and invoke git_config() directly on
platform_core_config().

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
I suspect the potential for a leak existed since the original implementation of
git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
0d6c2cb 
The primary goal of this change is to stop leaking init_db_template_dir. This
leak can happen because:
1. git_init_db_config() allocates new memory into init_db_template_dir without
   first freeing.
2. init_db_template_dir might already contain data, either because:
 2.1 git_config() can be invoked twice with this callback in a single process -
     at least 2 allocations are likely.
 2.2 A single git_config() allocation can invoke the callback multiple times for
     a given key (see further explanation in the function docs) - each of those
     calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir) before
overwriting it. Instead we convert to git_config_get_value() as that is more
explicit, seemingly more efficient, AND avoids allocations (the returned result
is owned by the config cache, so we aren't responsible for freeing it).

By removing init_db_template_dir, git_init_db_config() ends up only being
responsible for forwarding core.* config values to platform_core_config().
However platform_core_config() already ignores non-core.* config values,
so we can safely remove git_init_db_config() and invoke git_config() directly on
platform_core_config().

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
I suspect the potential for a leak existed since the original implementation of
git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
ccfd30a 
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in:
  f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
vv    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
eb94a86 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
107e98d 
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in:
  f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
vv    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 8, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
d30365d 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
gitster pushed a commit that referenced this pull request Mar 8, 2021
@ahunt @gitster
clone: free or UNLEAK further pointers when finished
c6f4898 
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in:
  f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
vv    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
gitster pushed a commit that referenced this pull request Mar 8, 2021
@ahunt @gitster
init: remove git_init_db_config() while fixing leaks
3a2c316 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    #8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    #9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    #10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    #11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    #12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    #13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    #14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
4c1adf2 
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in:
  f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
27d35ae 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
0104768 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is  already responsible for most of
transport's cleanup - therefore that sems like the most logical place to
free remote_refs.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used.

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
3598a85 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is  already responsible for most of
transport's cleanup - therefore that sems like the most logical place to
free remote_refs.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used.

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
2795ad9 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is  already responsible for most of
transport's cleanup - therefore that sems like the most logical place to
free remote_refs.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used.

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
clone: free or UNLEAK further pointers when finished
a74bbca 
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().

We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in:
  f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17)

These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
    #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 178 byte(s) in 1 object(s) allocated from:
    #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
    #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
    #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
    #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
    #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
    #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 105 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
    #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
    #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
    #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
    #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
0f82d07 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
0cb7457 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is already responsible for most of
transport's cleanup - therefore we also take care of freeing remote_refs
there.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used - which is necessary to safely be able to
free remote_refs during transport_disconnect().

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
360171f 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is already responsible for most of
transport's cleanup - therefore we also take care of freeing remote_refs
there.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used - which is necessary to safely be able to
free remote_refs during transport_disconnect().

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
init: remove git_init_db_config() while fixing leaks
206a822 
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b4518 (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    git#8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    git#9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    git#10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    git#11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    git#12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    git#13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    git#14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 14, 2021
@ahunt
transport: also free remote_refs in transport_disconnect()
a907f24 
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is already responsible for most of
transport's cleanup - therefore we also take care of freeing remote_refs
there.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used - which is necessary to safely be able to
free remote_refs during transport_disconnect().

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    git#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    git#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    git#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 15, 2021
@ahunt
fsmonitor: avoid global-buffer-overflow READ when checking trivial re…
4b7b276 
…sponse

query_result can be be an empty strbuf (STRBUF_INIT) - in that case
trying to read 3 bytes triggers a buffer overflow read.

Therefore we need to check query_result's length before trying to read 3
bytes.

This was found when running the test-suite against ASAN, and could be
reproduced with the following command:

make GIT_TEST_OPTS="-v" DEFAULT_TEST_TARGET="t7519-status-fsmonitor.sh" \
SANITIZE=address DEVELOPER=1 test

==2235==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000019e6e5e at pc 0x00000043745c bp 0x7fffd382c520 sp 0x7fffd382bcc8
READ of size 3 at 0x0000019e6e5e thread T0
    #0 0x43745b in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7
    #1 0x43786d in bcmp /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:887:10
    #2 0x80b146 in fsmonitor_is_trivial_response /home/ahunt/oss-fuzz/git/fsmonitor.c:192:10
    #3 0x80b146 in query_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:175:7
    #4 0x80a749 in refresh_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:267:21
    #5 0x80bad1 in tweak_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:429:4
    #6 0x90f040 in read_index_from /home/ahunt/oss-fuzz/git/read-cache.c:2321:3
    #7 0x8e5d08 in repo_read_index_preload /home/ahunt/oss-fuzz/git/preload-index.c:164:15
    git#8 0x52dd45 in prepare_index /home/ahunt/oss-fuzz/git/builtin/commit.c:363:6
    git#9 0x52a188 in cmd_commit /home/ahunt/oss-fuzz/git/builtin/commit.c:1588:15
    git#10 0x4ce77e in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4ccb18 in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4cb01c in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cb01c in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x6aca8d in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7fb027bf5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
    git#16 0x4206b9 in _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120

0x0000019e6e5e is located 2 bytes to the left of global variable 'strbuf_slopbuf' defined in 'strbuf.c:51:6' (0x19e6e60) of size 1
  'strbuf_slopbuf' is ascii string ''
0x0000019e6e5e is located 126 bytes to the right of global variable 'signals' defined in 'sigchain.c:11:31' (0x19e6be0) of size 512
SUMMARY: AddressSanitizer: global-buffer-overflow /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long)
Shadow bytes around the buggy address:
  0x000080334d70: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334db0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
=>0x000080334dc0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9[f9]01 f9 f9 f9
  0x000080334dd0: f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9 02 f9 f9 f9
  0x000080334de0: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
  0x000080334df0: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334e00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 01 f9 f9 f9
  0x000080334e10: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
ahunt added a commit to ahunt/git that referenced this pull request Mar 15, 2021
@ahunt
fsmonitor: avoid global-buffer-overflow READ when checking trivial re…
cdbeb03 
…sponse

query_result can be be an empty strbuf (STRBUF_INIT) - in that case
trying to read 3 bytes triggers a buffer overflow read.

Therefore we need to check query_result's length before trying to read 3
bytes.

This overflow was introduced in:
  940b94f (fsmonitor: log invocation of FSMonitor hook to trace2, 2021-02-03)

It was found when running the test-suite against ASAN, and could be
reproduced with the following command:

make GIT_TEST_OPTS="-v" DEFAULT_TEST_TARGET="t7519-status-fsmonitor.sh" \
SANITIZE=address DEVELOPER=1 test

==2235==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000019e6e5e at pc 0x00000043745c bp 0x7fffd382c520 sp 0x7fffd382bcc8
READ of size 3 at 0x0000019e6e5e thread T0
    #0 0x43745b in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7
    #1 0x43786d in bcmp /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:887:10
    #2 0x80b146 in fsmonitor_is_trivial_response /home/ahunt/oss-fuzz/git/fsmonitor.c:192:10
    #3 0x80b146 in query_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:175:7
    #4 0x80a749 in refresh_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:267:21
    #5 0x80bad1 in tweak_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:429:4
    #6 0x90f040 in read_index_from /home/ahunt/oss-fuzz/git/read-cache.c:2321:3
    #7 0x8e5d08 in repo_read_index_preload /home/ahunt/oss-fuzz/git/preload-index.c:164:15
    git#8 0x52dd45 in prepare_index /home/ahunt/oss-fuzz/git/builtin/commit.c:363:6
    git#9 0x52a188 in cmd_commit /home/ahunt/oss-fuzz/git/builtin/commit.c:1588:15
    git#10 0x4ce77e in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    git#11 0x4ccb18 in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    git#12 0x4cb01c in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    git#13 0x4cb01c in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    git#14 0x6aca8d in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    git#15 0x7fb027bf5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
    git#16 0x4206b9 in _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120

0x0000019e6e5e is located 2 bytes to the left of global variable 'strbuf_slopbuf' defined in 'strbuf.c:51:6' (0x19e6e60) of size 1
  'strbuf_slopbuf' is ascii string ''
0x0000019e6e5e is located 126 bytes to the right of global variable 'signals' defined in 'sigchain.c:11:31' (0x19e6be0) of size 512
SUMMARY: AddressSanitizer: global-buffer-overflow /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long)
Shadow bytes around the buggy address:
  0x000080334d70: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334db0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
=>0x000080334dc0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9[f9]01 f9 f9 f9
  0x000080334dd0: f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9 02 f9 f9 f9
  0x000080334de0: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
  0x000080334df0: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334e00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 01 f9 f9 f9
  0x000080334e10: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
@excitoon excitoon mentioned this pull request Aug 26, 2022
Open
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3 participants

@GunioRobot @gitster @cowlicks