1320192 - [a11y] Flash player crashes on 51.0b2 32bitwith e10s when Windows10 Narrator is activated

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Alice0775 White]

Attachment: screenshot

[Tracking Requested - why for this release]: Flash Player crashes when Narrator is activated

Build Identifier:
https://hg.mozilla.org/releases/mozilla-beta/rev/749a8d32b74eae516b9427f28aad4ec1c11e0a54
Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0 ID:20161115182233

Flash Player 23.0.0.207 crashes when Windows10 Narrator is activated.

Affected to:
Firefox51.0b2 32bit w/ e10s.
Aurora52.0a2 32bit w/ e10s & dom.ipc.plugins.asyncdrawing.enabled=false.
Nightly53.0a1 32bit w/ e10s & dom.ipc.plugins.asyncdrawing.enabled=false & security.sandbox.content.level=1.

Reproducible : often

Steps To Reproduce:
1. Activate Narrator
   (Win+U then turn on)
2. Start Firefox51.0b2 with e10s
3. Open http://emk.name/test/swftxt.html
4. Repeatedly Double click on page if necessary

Actual Results:
Flash player crashes. See attached screenshot

Expected Results:
No crash

Comment 1

[Alice0775 White]

Firefox50.0 32bit w/ e10s is also affected.

Comment 2

[Alice0775 White]

Attachment: Settings narrator

Comment 3

[Alice0775 White]

also affected to:
Firefox50.0 crashes without e10s.
Firefox51.0b3 crashes without e10s.
Aurora52.0a2 crashes without e10s & dom.ipc.plugins.asyncdrawing.enabled=false.
Nightly53.0a1 crashes without e10s & dom.ipc.plugins.asyncdrawing.enabled=false & security.sandbox.content.level=1.

#2 Steps To Reproduce:
1. Activate Narrator
   (Win+U then turn on)
2. Start Firefox51.0b2 without e10s
3. Open http://emk.name/test/swftxt.html
   --- sometimes flash plugin crashes
4. Open http://emk.name/test/swftxt.html in a new tab
   --- sometimes flash plugin crashes

Comment 4

[Alice0775 White]

bp-d3980c63-f63d-43ac-a644-d57362161125
bp-2f406494-8ace-4ed4-9c72-c04442161125
bp-2b072571-e04b-4740-b986-578e12161125
bp-8d579e75-2fde-4bc6-a1e9-ab04e2161125

Comment 5

[Benjamin Smedberg]

Seems that this is not e10s-specific but is a stack overflow, but related to a11y:

19 	xul.dll 	NeuteredWindowProc(HWND__*, unsigned int, unsigned int, long) 	ipc/glue/WindowsMessageLoop.cpp:458
Ø 20 	user32.dll 	user32.dll@0x2d2b2 	
Ø 21 	user32.dll 	user32.dll@0xe889 	
Ø 22 	user32.dll 	user32.dll@0xdf16 	
23 	xul.dll 	`anonymous namespace'::ProcessOrDeferMessage 	ipc/glue/WindowsMessageLoop.cpp:404
24 	xul.dll 	NeuteredWindowProc(HWND__*, unsigned int, unsigned int, long)

ad infinitum.

Jim, this seems like it's not an Adobe bug but ours. Alice, does this have a recent-ish (after FF42 or so) Firefox regression range, if you keep the Flash version consistent?

Comment 6

[Alice0775 White]

At least Firefox38.8ESR, Firefox45.5ESR, Firefox47.0.2, 48.0.0, 49.0.2 crashes.
(I am not sure but it seems a timing out related to Bug 732872.)

Comment 7

[(No longer employed by Mozilla) Aaron Klotz]

Ah, Window neutering, we meet again.

Comment 8

[(No longer employed by Mozilla) Aaron Klotz]

This is quite likely caused by the same problem as bug 1319640. Once that lands we should retest this.

Comment 9

[(No longer employed by Mozilla) Aaron Klotz]

Alice, are you still seeing this after bug 1319640 landed?

Comment 10

[Alice0775 White]

Tab crashes on latest Nightly.
bp-539f1a86-9fad-4fb5-9f1b-b28422161207
bp-63e64e04-8d33-47b4-8e78-e3a012161207

[1]https://hg.mozilla.org/mozilla-central/rev/8103c612b79c2587ea4ca1b0a9f9f82db4b185b8
Mozilla/5.0 (Windows NT 10.0; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0 ID:20161206030203

Comment 11

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Patch

In the e10s case, we'll return IPC_OK() and the native accessible will be nullptr. In the non-e10s case, we make sure that mHwnd is either the "real" plugin HWND or null, which we correctly handle.

Comment 12

[(No longer employed by Mozilla) Aaron Klotz]

https://hg.mozilla.org/integration/mozilla-inbound/rev/653e7327b3f835cdc42de5632f8831f1616fcddc
Bug 1320192: Ensure that we return a null native accessible if GetWindow(GW_CHILD) on a windowed plugin fails; r=tbsaunde

Comment 13

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/653e7327b3f8

Comment 14

[(No longer employed by Mozilla) Aaron Klotz]

Comment on attachment 8817209 [details] [diff] [review]
Patch

Approval Request Comment
[Feature/Bug causing the regression]: a11y on windows with plugins (both e10s and non-e10s)
[User impact if declined]: Crashes
[Is this code covered by automated tests?]: No
[Has the fix been verified in Nightly?]: Yes
[Needs manual test from QE? If yes, steps to reproduce]: No
[List of other uplifts needed for the feature/fix]: None
[Is the change risky?]: No
[Why is the change risky/not risky?]: Trivial patch
[String changes made/needed]: None

Comment 15

[Julien Cristau [:jcristau]]

Comment on attachment 8817209 [details] [diff] [review]
Patch

a11y/windows/plugin fix for aurora52

Comment 16

[Carsten Book [:Tomcat]]

need rebasing for aurora

Comment 17

[(No longer employed by Mozilla) Aaron Klotz]

https://hg.mozilla.org/releases/mozilla-aurora/rev/00ced46aa9d09f6db2f9d9aa2483aaf9cf66e460

Comment 18

[Andrei Vaida [:avaida]]

We should be verifying this on 52 Beta.

Comment 19

[Bogdan Maris [:bogdan_maris], Desktop QA]

I was able to crash Firefox 51.0.1 using the steps from comment 0 on Windows 10 32bit. 
bp-62608a07-b4cd-4c0c-bce8-587ff2170210
bp-d891970e-14c0-4fdb-ad61-94e5a2170210

I was NOT able to crash Firefox 52 beta 5 on the same platform, so I'm gonna mark as verified on 52.

Comment 20

[Andrei Vaida [:avaida]]

Removing the qe-verify flag since this has been confirmed fixed on Fx52 (see Comment 19), which has now been released.