Messages in this thread Patch in this message | | | Date | Fri, 24 Sep 2010 09:24:29 -0700 | From | Greg KH <> | Subject | [41/80] drivers/video/sis/sis_main.c: prevent reading uninitialized stack memory |
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2.6.35-stable review patch. If anyone has any objections, please let us know.
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From: Dan Rosenberg <drosenberg@vsecurity.com>
commit fd02db9de73faebc51240619c7c7f99bee9f65c7 upstream.
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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/video/sis/sis_main.c | 3 +++ 1 file changed, 3 insertions(+)
--- 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 *i break; case FBIOGET_VBLANK: + + memset(&sisvbblank, 0, sizeof(struct fb_vblank)); + sisvbblank.count = 0; sisvbblank.flags = sisfb_setupvbblankflags(ivideo, &sisvbblank.vcount, &sisvbblank.hcount);
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