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Bug 760330 - idle-monitor-xsync: fix crash if watch callback removes different watch
idle-monitor-xsync: fix crash if watch callback removes different watch
Status: RESOLVED FIXED
Product: mutter
Classification: Core
Component: general
unspecified
Other All
: Normal normal
: ---
Assigned To: mutter-maint
mutter-maint
Depends on:
Blocks:
 
 
Reported: 2016-01-08 18:24 UTC by Ray Strode [halfline]
Modified: 2016-01-11 16:25 UTC
See Also:
GNOME target: ---
GNOME version: ---

Attachments
idle-monitor-xsync: fix crash if watch callback removes different watch (5.93 KB, patch)
2016-01-08 18:24 UTC, Ray Strode [halfline] 		none Details | Review
idle-monitor-xsync: fix crash if watch callback removes different watch (5.95 KB, patch)
2016-01-08 18:26 UTC, Ray Strode [halfline] 		committed Details | Review

Description Ray Strode [halfline] 2016-01-08 18:24:47 UTC 
Right now the XSync based idle monitoring code, will fetch all active
watches into a list, and then call their watch callbacks one by one
as necessary.  If one watch callback invalidates another watch, the
list will contain free'd memory.

This commit makes sure to consult the hash table after ever call
of a watch callback, to ensure mutter never looks at freed memory.

Fixes crash reported on IRC by Laine Stump with his synergy setup.
Comment 1 Ray Strode [halfline] 2016-01-08 18:24:51 UTC 
Created attachment 318534 [details] [review]
idle-monitor-xsync: fix crash if watch callback removes different watch
Comment 2 Ray Strode [halfline] 2016-01-08 18:25:49 UTC 
oh hang on, i manually frobbed the patch file when doing a test rpm build and didn't update git.
Comment 3 Ray Strode [halfline] 2016-01-08 18:26:56 UTC 
Created attachment 318536 [details] [review]
idle-monitor-xsync: fix crash if watch callback removes different watch

Right now the XSync based idle monitoring code, will fetch all active
watches into a list, and then call their watch callbacks one by one
as necessary.  If one watch callback invalidates another watch, the
list will contain free'd memory.

This commit makes sure to consult the hash table after ever call
of a watch callback, to ensure mutter never looks at freed memory.

Fixes crash reported on IRC by Laine Stump with his synergy setup.
Comment 4 Rui Matos 2016-01-11 16:16:21 UTC 
Review of attachment 318536 [details] [review]:

Looks good. See also bug 760476
Comment 5 Ray Strode [halfline] 2016-01-11 16:25:16 UTC 
Attachment 318536 [details] pushed as 42b3a34 - idle-monitor-xsync: fix crash if watch callback removes different watch