Tabs in Firefox 74.0 crash on some websites: [GFX1-]: DrawTargetCairo::Snapshot with bad surface (when gfx.canvas.azure.backends has been modified to "cairo")

[Ary Moonc]

Ubuntu: 19.10
Firefox: 74.0+build3-0ubuntu0.19.10.1

Since 2020.03.31 tabs in Firefox started to crash regularly on some websites (mainly Vbulletin and phpBB forums).
This happens also in --safe-mode.

stderr output (just this one line):

[GFX1-]: DrawTargetCairo::Snapshot with bad surface 0x7efdd6d99b00, context 0x7efdd5cba000, status 0

When trying to reload tabs they keep crashing, but after like 10-20 retries they display properly and continue to work fine.

Example of a website that regularly crashes Firefox:
https://aryion.com/forum/

[Olivier Tilloy (osomon)]

Can you open "about:crashes" in a new tab, and check whether there are reports corresponding to the timestamps when you experienced the problem? Have they been submitted?

Did the problem start happening just after installing a firefox update? (i.e. were you using an older version before yesterday?)

[Ary Moonc (arymoonc)]

It started happening from 3/30/20 6:54 PM (first related crash in about:crashes).
I did an usual system update before, but nothing really related to Firefox (aptitude log attached).

I submitted some of the newest crash logs:
https://crash-stats.mozilla.org/report/index/7f40c34c-296f-4cbb-b969-8e1f00200401
https://crash-stats.mozilla.org/report/index/1c80aca5-a292-4eec-b536-d56a20200401
https://crash-stats.mozilla.org/report/index/474db221-c61f-4128-b657-68c140200401
https://crash-stats.mozilla.org/report/index/f2f893eb-5426-4efe-a928-f62e90200401
https://crash-stats.mozilla.org/report/index/486df46e-7963-4719-bbe1-524d60200401

[Olivier Tilloy (osomon)]

Thanks for the additional information.

I'm marking the bug confirmed, per the upstream crash reports. Hopefully this will be investigated upstream.

The only thing that stands out in your updates' log is the kernel one.

[Ary Moonc (arymoonc)]

>The only thing that stands out in your updates' log is the kernel one.

I've rebooted to the previous 5.3.0-42-lowlatency, but the issue still occurs:

https://crash-stats.mozilla.org/report/index/5b65eac0-1b91-4afc-a75b-80f040200404

[Ary Moonc (arymoonc)]

The problem seems to be SOLVED now after updating nVidia drivers (see attached aptitude log).

Firefox also got updated some time before (included in log), but that didn't solve the problem on its own.

[Olivier Tilloy (osomon)]

Excellent, thanks for following up. I'm glad the issue is fixed for you. I'll close the bug, feel free to re-open if the problem resurfaces.

[Ary Moonc (arymoonc)]

Unfortunately the issue is back. With no action from my side (software or plugin installation or update).

It was perfectly fine after https://bugzilla.mozilla.org/show_bug.cgi?id=1627689#c2 - from 2020-04-09 to 2020-04-14.
But today I just had those crashes again.
Reproducible after restarting the browser (clean history, cookies), even in --safe-mode.

https://crash-stats.mozilla.org/report/index/4cae681d-1453-496b-8303-2aeff0200415

This related bug report was reported upstream: https://bugzilla.mozilla.org/show_bug.cgi?id=1627689

[Ary Moonc (arymoonc)]

I have reviewed my "about:support" contents and found preference "gfx.canvas.azure.backends" modified to "cairo" (from default "skia").
Toggling this entry between those two values (and restarting the browser) seems to fix/reproduce the issue 100% of the time.

I also had "gfx.content.azure.backends" set alike, but changing this does not seem to have any negative effect.

So with both set to "skia" the issue seems solved for me.

[Olivier Tilloy (osomon)]

Good finding, thanks for following up Ary.