1746300 - Crash in [@ mozilla::net::ProxyAutoConfigChild::RecvGetProxyForURI]

Status: RESOLVED FIXED

(Core :: Networking: HTTP, defect, P2)

Description

[Andrew McCreight [:mccr8]]

Maybe Fission related. (DOMFissionEnabled=1)

Crash report: https://crash-stats.mozilla.org/report/index/93584e14-7f31-4c2a-a1ef-864ae0211215

Reason: EXCEPTION_ACCESS_VIOLATION_READ

Top 10 frames of crashing thread:

0 xul.dll mozilla::net::ProxyAutoConfigChild::RecvGetProxyForURI netwerk/ipc/ProxyAutoConfigChild.cpp:154
1 xul.dll mozilla::detail::RunnableFunction<`lambda at /builds/worker/checkouts/gecko/netwerk/ipc/ProxyAutoConfigChild.cpp:158:9'>::Run xpcom/threads/nsThreadUtils.h:531
2 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:1177
3 xul.dll mozilla::ipc::MessagePumpForNonMainThreads::Run ipc/glue/MessagePump.cpp:300
4 xul.dll MessageLoop::RunHandler ipc/chromium/src/base/message_loop.cc:324
5 xul.dll MessageLoop::Run ipc/chromium/src/base/message_loop.cc:306
6 xul.dll static nsThread::ThreadFunc xpcom/threads/nsThread.cpp:391
7 nss3.dll _PR_NativeRunThread nsprpub/pr/src/threads/combined/pruthr.c:399
8 nss3.dll pr_root nsprpub/pr/src/md/windows/w95thred.c:139
9 ucrtbase.dll thread_start<unsigned int , 1> 

This looks like a null deref, on this line:
if (mPAC->WaitingForDNSResolve()) {

Maybe this method is getting called after ActorDestroy?

Comment 1

[Andrew McCreight [:mccr8]]

4 crashes from 4 install times, in the 20211214094205 build of 97.0a1, so maybe it is a regression.

Comment 2

[Andrew McCreight [:mccr8]]

I think this is the set of new changes in that build. Nothing jumps out as me, though there are a few things that talk about IPC or the socket process.

Comment 3

[Kershaw Chang [:kershaw]]

Attachment: Bug 1746300 - Add some null checks and avoid busy waiting for DNS resolution, r=#necko

Comment 4

[Kershaw Chang [:kershaw]]

This is regressed by bug 1745385.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1745385

Comment 6

[Andrew McCreight [:mccr8]]

(FWIW, I filed this based on the "Spikes in signatures" report.)

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3086ed65de58
Add some null checks and avoid busy waiting for DNS resolution, r=necko-reviewers,valentin

Comment 8

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/3086ed65de58