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Bug 5456 - Invalid memcpy inside SDL_GestureDelTouch
Summary: Invalid memcpy inside SDL_GestureDelTouch
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: events (show other bugs)
Version: HG 2.1
Hardware: Other Android (All)
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-01-10 13:11 UTC by Yuki Okumura
Modified: 2021-01-10 21:22 UTC (History)
1 user (show)

See Also:

Attachments
src/events/SDL_gesture.c: Patch proposal (920 bytes, patch)
2021-01-10 13:11 UTC, Yuki Okumura 		Details | Diff
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Description Yuki Okumura 2021-01-10 13:11:34 UTC 
Created attachment 4655 [details]
src/events/SDL_gesture.c: Patch proposal

(Reported as: https://github.com/spurious/SDL-mirror/pull/14 )

In function SDL_GestureDelTouch(), when deleting the final entry it might do overlapping memcpy because it might do:

> SDL_memcpy(&SDL_gestureTouch[0], &SDL_gestureTouch[0], sizeof(SDL_gestureTouch[i]));

memcpy should not be used for overlapping region, but anyway, it does not need to be done.

Attached is @dmikushin's patch that adds check and skip memcpy when removing the final entry.
Comment 1 Sylvain 2021-01-10 21:22:46 UTC 
Thanks, added in :
https://hg.libsdl.org/SDL/rev/17d911637a65

slightly differently: checking: (i != SDL_numGestureTouches)