1582966 - Crash in [@ mozilla::net::FTPChannelParent::NotifyDiversionFailed]

Status: RESOLVED FIXED

(Core Graveyard :: Networking: FTP, defect, P1)

Description

[[:philipp]]

This bug is for crash report bp-abfd111b-ab3a-42cd-8196-dfb580190918.

Top 10 frames of crashing thread:

0 xul.dll void mozilla::net::FTPChannelParent::NotifyDiversionFailed netwerk/protocol/ftp/FTPChannelParent.cpp:784
1 xul.dll nsresult mozilla::net::FTPFailDiversionEvent::Run netwerk/protocol/ftp/FTPChannelParent.cpp:760
2 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:1225
3 xul.dll NS_ProcessNextEvent xpcom/threads/nsThreadUtils.cpp:486
4 xul.dll mozilla::ipc::MessagePump::Run ipc/glue/MessagePump.cpp:88
5 xul.dll MessageLoop::RunHandler ipc/chromium/src/base/message_loop.cc:308
6 xul.dll MessageLoop::Run ipc/chromium/src/base/message_loop.cc:290
7 xul.dll nsBaseAppShell::Run widget/nsBaseAppShell.cpp:137
8 xul.dll nsAppShell::Run widget/windows/nsAppShell.cpp:406
9 xul.dll nsresult nsAppStartup::Run toolkit/components/startup/nsAppStartup.cpp:276

these crashes are starting to show up in fairly low volume in the firefox 70 cycle.
and happen with MOZ_RELEASE_ASSERT(mDivertToListener) from bug 975338. (https://dxr.mozilla.org/mozilla-central/source/netwerk/protocol/ftp/FTPChannelParent.cpp#779).

the first recorded crash occurred on 70.0a1 build 20190819095406, the only submitted user comment so far says: "I clicked on a ftp link, it prompted me to download something, i canceled and then firefox crashed."

Comment 1

[Junior [inactive]]

I can't proceed to reproduce (See bug 1576171 comment 11)
P3 given lower crash rate, but it might be hidden by other crashes.

We wrongly called FailDiversion [1] twice so that the listener is null'ed by the first NotifyDiversionFailed
[1] https://searchfox.org/mozilla-central/rev/153feabebc2d13bb4c29ef8adf104ec1ebd246ae/netwerk/protocol/ftp/FTPChannelParent.cpp#776

Comment 2

[Liz Henry (:lizzard) (relman/hg->git project)]

The crash volume is pretty significant for beta. Once this gets to 70 release I expect it will be high. Can you take another look? Is it something we could possibly patch next week in beta 13 or 14?

Comment 3

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

Changing the priority to p1 as the bug is tracked by a release manager for the current beta.
See What Do You Triage for more information

Comment 4

[Junior [inactive]]

I can't reproduce (see comment 1).
After a deep look, I'm confident with a patch with bold hypothesis.

It should be a 5 years old bug, revealed by enabling bug 1560699

Comment 5

[Junior [inactive]]

Attachment: Bug 1582966 - avoid double failure handling for FTP

caller of ResumeForDiversion should respond for error handling

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a9896a6ae8af
avoid double failure handling for FTP r=valentin

Comment 7

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/a9896a6ae8af

Comment 8

[Junior [inactive]]

FTP is not well unit tested.
Let's uplift to beta after we're sure no major regressions in nightly for days.

Hope it's a lucky punch. Finger crossed.

Comment 9

[Junior [inactive]]

Comment on attachment 9098408 [details]
Bug 1582966 - avoid double failure handling for FTP

Beta/Release Uplift Approval Request

• User impact if declined: 4-6 crashes per day in beta, expected more in release
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): small change. no major issue in nightly
• String changes made/needed:

Comment 10

[Liz Henry (:lizzard) (relman/hg->git project)]

Comment on attachment 9098408 [details]
Bug 1582966 - avoid double failure handling for FTP

Crash fix, let's get this lucky punch into beta 13.

Comment 11

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/releases/mozilla-beta/rev/281ce5e6022b

Comment 12

[Junior [inactive]]

Beta 13 is going out tomorrow. We have 4-6 crashes a day, which should be observable.

Comment 13

[Junior [inactive]]

70.0b13 20191007220302 is with the change.