Messages in this thread Patch in this message | | | Subject | [PATCH] drivers/video/sis/sis_main.c: prevent reading uninitialized stack memory | From | Dan Rosenberg <> | Date | Wed, 15 Sep 2010 17:43:53 -0400 |
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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>
--- linux-2.6.35.4.orig/drivers/video/sis/sis_main.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/video/sis/sis_main.c 2010-09-15 11:52:41.437375730 -0400 @@ -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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