1380106 - stylo: Crash in do_QueryFrame::operator<T> nsIAnonymousContentCreator*

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P1)

Description

[Marcia Knous [:marcia]]

This bug was filed from the Socorro interface and is 
report bp-88e599f9-e12a-4ba9-82d1-29b520170711.
=============================================================

Seen in crash stats: http://bit.ly/2tFdqYl

Some URLs:

https://www.lineageoslog.com/build
https://download.mokeedev.com/?device=hlte

Comment 1

[Bobby Holley (:bholley)]

So, I'm not really sure why do_QueryFrame is crashing, but given that this is during document teardown it seems possible that we may have destroyed the arena but not yet nulled out the element->frame pointer.

Either way, we call FragmentOrElement::DestroyContent, which calls nsBindingManager::RemovedFromDocumentInternal, which calls FragmentOrElement::SetXBLInsertionParent, which tries to recursively clear servo data from the subtree:

https://hg.mozilla.org/mozilla-central/annotate/0e41d07a703f/dom/base/FragmentOrElement.cpp#l1221

We really don't need to be doing that at all given that this is during teardown. So it might make sense to just clear the servo data at the top of FragmentOrElement::DestroyContent. I'll try.

Comment 2

[Bobby Holley (:bholley)]

Attachment: Drop style data in DestroyContent. v1

MozReview-Commit-ID: 9ydkvlDA9oS

Comment 3

[Bobby Holley (:bholley)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=70de977c034515f3904dcd635d9dc7acbc2b855c

Comment 4

[Cameron McCormack (:heycam)]

Comment on attachment 8885427 [details] [diff] [review]
Drop style data in DestroyContent. v1

Review of attachment 8885427 [details] [diff] [review]:
-----------------------------------------------------------------

I suppose this is OK, although I would prefer something less indirect, e.g. a check in FragmentOrElement::SetXBLInsertionParent that we're not in the middle of destroying the document (e.g. by checking nsDocument::mIsGoingAway, although that's not exposed).

Comment 5

[Bobby Holley (:bholley)]

Boris was concerned as to why we'd be hitting this, and was going to try reproducing locally.

Comment 6

[Boris Zbarsky [:bzbarsky]]

So I tried adding checks to FragmentOrElement::DestroyContent to yell if GetPrimaryFrame() is non-null.  It never is, for me, on the urls in comment 0, as expected.

I tried installing uBlock Origin (since the crash dump above seems to have it installed), but that does not seem to change things.  Not sure whether one of the other addons is relevant here...

Anyway, the change in this bug makes sense to me, I think, though I agree it fixing the bug is not quite obvious.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/795947f535e8
Drop style data in DestroyContent. r=heycam,r=bz

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/795947f535e8