1829641 - Crash in [@ mozilla::gmp::GMPChild::GetUTF8LibPath]

Status: RESOLVED FIXED

(Core :: Audio/Video: GMP, defect, P3)

Description

[Andrew Osmond [:aosmond] (he/him)]

Crash report: https://crash-stats.mozilla.org/report/index/b304089d-e157-4d77-b772-4288f0230420

MOZ_CRASH Reason: MOZ_CRASH(Failed to normalize plugin file)

Top 10 frames of crashing thread:

0  libxul.so  mozilla::gmp::GMPChild::GetUTF8LibPath  dom/media/gmp/GMPChild.cpp:278
1  libxul.so  mozilla::gmp::GMPChild::RecvStartPlugin  dom/media/gmp/GMPChild.cpp:496
2  libxul.so  mozilla::gmp::PGMPChild::OnMessageReceived  ipc/ipdl/PGMPChild.cpp:787
3  libxul.so  mozilla::ipc::MessageChannel::DispatchSyncMessage  ipc/glue/MessageChannel.cpp:1767
3  libxul.so  mozilla::ipc::MessageChannel::DispatchMessage  ipc/glue/MessageChannel.cpp:1723
4  libxul.so  mozilla::ipc::MessageChannel::RunMessage  ipc/glue/MessageChannel.cpp:1525
4  libxul.so  mozilla::ipc::MessageChannel::MessageTask::Run  ipc/glue/MessageChannel.cpp:1623
5  libxul.so  MessageLoop::RunTask  ipc/chromium/src/base/message_loop.cc:492
5  libxul.so  MessageLoop::DeferOrRunPendingTask  ipc/chromium/src/base/message_loop.cc:501
5  libxul.so  MessageLoop::DoWork  ipc/chromium/src/base/message_loop.cc:576

Comment 1

[Andrew Osmond [:aosmond] (he/him)]

The recent crash reports provide the evidence that it is indeed the path normalization/resolving links that is failing in the plugin process. Windows specifically is hitting a permission denied failure case.

The solution is just to not do this in the plugin process. We already are supposed to be resolving links/normalizing the path passed into the plugin process, so there is no need to do it again. Our only option is to just trust the path since we aren't privileged enough to verify it anyways.

Comment 2

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1829641 - Only normalize file paths in parent in behalf of GMP process.

This patch makes the parent process fully normalize paths before
passing it to the GMP plugin process. Now the plugin process can
avoid trying to normalize itself and run into sandboxing issues.
This was causing one form of startup crashes for Widevine.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/65f977e5ade4
Only normalize file paths in parent in behalf of GMP process. r=media-playback-reviewers,alwu

Comment 4

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/65f977e5ade4

Comment 5

[Cristina Horotan [:chorotan]]

Backed out for causing build bustages at GMPProcessParent.cpp

Backout: https://hg.mozilla.org/mozilla-central/rev/a5a273e3b1fdbeb8890d8bdd48d56cdee6ddbcb3

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0cbfc693e930
Only normalize file paths in parent in behalf of GMP process. r=media-playback-reviewers,alwu

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/0cbfc693e930