Skip to content

Remove extra check that the system dll exists #10244

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
TravisEz13 merged 2 commits into from
Aug 5, 2019
Merged

Remove extra check that the system dll exists #10244

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
391294e
Remove extra check that system dll exists
iSazonov Jul 29, 2019
3b8ed17
Add travis and paul as codeowners for wldpnativemethods
TravisEz13 Jul 29, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions .github/CODEOWNERS
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@

# Area: Security
# @TravisEz13 @PaulHigin
src/System.Management.Automation/security/wldpNativeMethods.cs @TravisEz13 @PaulHigin

# Area: Documentation
.github/ @joeyaiello @TravisEz13
Expand Down
3 changes: 1 addition & 2 deletions src/System.Management.Automation/security/wldpNativeMethods.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -113,9 +113,8 @@ public static SystemEnforcementMode GetLockdownPolicy(string path, SafeHandle ha
private static SystemEnforcementMode GetWldpPolicy(string path, SafeHandle handle)
{
// If the WLDP assembly is missing (such as windows 7 or down OS), return default/None to skip WLDP validation
if (s_hadMissingWldpAssembly || !IO.File.Exists(IO.Path.Combine(Environment.SystemDirectory, "wldp.dll")))
if (s_hadMissingWldpAssembly)
Copy link
Member

@TravisEz13 TravisEz13 Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is still needed for Operating System before Windows 10

Copy link
Member

@TravisEz13 TravisEz13 Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

cc @PaulHigin

Copy link
Contributor

@PaulHigin PaulHigin Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actually I feel this is the right fix. We catch the DllNotFoundException and set the s_hadMissingWldpAssembly field there. I don't see a need to check it every time at the top of the method.

Copy link
Collaborator Author

@iSazonov iSazonov Jul 30, 2019 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, it is already in the PR description.

I just do not understand why the security fix (mentioned in related issue) led to this problem if it is a long-standing code? Or is there still another problem?

Update: It seems wldp.dll is more slow after the security fix
After remove the extra file check we have for debug compilation:
image

image

for release compilation:
image

image

Output from test script is:

Without bp:     150
With bp:        1041

So we have still a noticeable delay in wldp.dll.
Is it acceptable to cache policy for each path or MSFT team will investigate wldp internally? For Pester scenario we can get a very large cache.

{
s_hadMissingWldpAssembly = true;
return s_cachedWldpSystemPolicy.GetValueOrDefault(SystemEnforcementMode.None);
}

Expand Down