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authorDan Rosenberg <drosenberg@vsecurity.com>2010-09-22 22:05:09 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-23 02:22:39 +0200
commitfd02db9de73faebc51240619c7c7f99bee9f65c7 (patch)
tree2781eada960ecdfbb407fd473b53011b30012fee /drivers/video/sis/sis_main.c
parentuml: fix compile warning (diff)
downloadlinux-fd02db9de73faebc51240619c7c7f99bee9f65c7.tar.xz
linux-fd02db9de73faebc51240619c7c7f99bee9f65c7.zip
drivers/video/sis/sis_main.c: prevent reading uninitialized stack memory
The FBIOGET_VBLANK device ioctl allows unprivileged users to read 16 bytes of uninitialized stack memory, because the "reserved" member of the fb_vblank struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/sis/sis_main.c')
-rw-r--r--drivers/video/sis/sis_main.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c
index 559bf1727a2b..b52f8e4ef1fd 100644
--- a/drivers/video/sis/sis_main.c
+++ b/drivers/video/sis/sis_main.c
@@ -1701,6 +1701,9 @@ static int sisfb_ioctl(struct fb_info *info, unsigned int cmd,
break;
case FBIOGET_VBLANK:
+
+ memset(&sisvbblank, 0, sizeof(struct fb_vblank));
+
sisvbblank.count = 0;
sisvbblank.flags = sisfb_setupvbblankflags(ivideo, &sisvbblank.vcount, &sisvbblank.hcount);