tree 63ffee25ae6f56a41ff227aea44556a2d16ee907
parent ff8147fe71246b81a48de5f37041b026b57d60ca
author Florian Tobias Schandinat <FlorianSchandinat@gmx.de> 1253663261 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1253716796 -0700

fb: fix fb_pan_display range check

Fix the range check for panning.  The current code fails to detect some
invalid values (very high ones that can occur if an app tries to move
further up/left than 0,0) as the check uses the unknown values for
calculation so that an overflow can occur.

To fix this it is sufficient to move the calculation to the right side to
use only trusted values.

Kai Jiang detected this problem and proposed an initial patch.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Kai Jiang <b18973@freescale.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>