1370772 - Load GMPs from C:\ProgramData on Windows

Status: NEW

(Core :: Audio/Video: GMP, defect, P2)

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

We've had a number of GMP process crashes reported on Windows as [@ mozilla::gmp::GMPChild::ProcessingError] and we think one cause of this is users having their Firefox profile stored in a directory which is behind a junction or symlink.

To solve this, we can have the GMP executed from C:\ProgramData, as that's much less likely to be stored behind a symlink/junction (moving ProgramData causes Windows Update to not work, so I assume people are unlikely to do this).

We'd need to either copy the GMP into C:\ProgramData right before executing it, or store it there permanently.

I think we should set the Access Controls on the GMP DLL in C:\ProgramData to be only accessible to the current user, so that other users can't tamper with the DLL before we execute it.

Comment 1

[Chris Pearce [:cpearce (Not reading bugmail)]]

It seems that by default (at least on Windows 10) files created in C:\ProgramData have read+exec permissions by the Users group. So we don't need to worry about other users writing to the files we write into C:\ProgramData; they won't have write permissions unless they already have admin privileges.

Comment 2

[camping]

Is there a way to implement this before a patch/fix is available? We recently upgraded our terminal servers to ESR 52.2.1 and we are hitting this issue.

I am also available to test, if needed.

Thanks

Comment 3

[Emma Humphries ☕️🎸🧞‍♀️✨ (she/they) [:emceeaich] (Pacific Time) use needinfo]

This is an assigned P1 bug without activity in two weeks. 

If you intend to continue working on this bug for the current release/iteration/sprint, remove the 'stale-bug' keyword.

Otherwise we'll reset the priority of the bug back to '--' on Monday, August 28th.

Comment 4

[Bulk Bug Changes for mreavy's org]

Mass change P1->P2 to align with new Mozilla triage process