bpo-41815: SQLite: segfault if backup called on closed database (GH-22322)

miss-islington · pdmccormick · web-flow · commit ca2d99d091a5 · 2020-09-21T15:00:34.000-07:00
GH- [bpo-41815](): SQLite: fix segfault if backup called on closed database Attempting to backup a closed database will trigger segfault: ```python import sqlite3 target = sqlite3.connect(':memory:') source = sqlite3.connect(':memory:') source.close() source.backup(target) ``` (cherry picked from commit bfee9fa) Co-authored-by: Peter McCormick <peter@pdmccormick.com>
diff --git a/Lib/sqlite3/test/backup.py b/Lib/sqlite3/test/backup.py
@@ -36,6 +36,13 @@ def test_bad_target_closed_connection(self):
         with self.assertRaises(sqlite.ProgrammingError):
             self.cx.backup(bck)
 
+    def test_bad_source_closed_connection(self):
+        bck = sqlite.connect(':memory:')
+        source = sqlite.connect(":memory:")
+        source.close()
+        with self.assertRaises(sqlite.ProgrammingError):
+            source.backup(bck)
+
     def test_bad_target_in_transaction(self):
         bck = sqlite.connect(':memory:')
         bck.execute('CREATE TABLE bar (key INTEGER)')
diff --git a/Misc/NEWS.d/next/Library/2020-09-19-23-14-54.bpo-41815.RNpuX3.rst b/Misc/NEWS.d/next/Library/2020-09-19-23-14-54.bpo-41815.RNpuX3.rst
@@ -0,0 +1,2 @@
+Fix SQLite3 segfault when backing up closed database. Patch contributed by
+Peter David McCormick.
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
@@ -1523,6 +1523,10 @@ pysqlite_connection_backup(pysqlite_Connection *self, PyObject *args, PyObject *
         sleep_ms = (int)ms;
     }
 
+    if (!pysqlite_check_thread(self) || !pysqlite_check_connection(self)) {
+        return NULL;
+    }
+
     if (!pysqlite_check_connection((pysqlite_Connection *)target)) {
         return NULL;
     }

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Fix SQLite3 segfault when backing up closed database. Patch contributed by`
	`2`	`+Peter David McCormick.`
Original file line number	Diff line number	Diff line change
`@@ -1523,6 +1523,10 @@ pysqlite_connection_backup(pysqlite_Connection self, PyObject args, PyObject *`
`1523`	`1523`	`sleep_ms = (int)ms;`
`1524`	`1524`	`}`
`1525`	`1525`
	`1526`	`+ if (!pysqlite_check_thread(self) \|\| !pysqlite_check_connection(self)) {`
	`1527`	`+ return NULL;`
	`1528`	`+ }`
	`1529`	`+`
`1526`	`1530`	`if (!pysqlite_check_connection((pysqlite_Connection *)target)) {`
`1527`	`1531`	`return NULL;`
`1528`	`1532`	`}`