From fd02db9de73faebc51240619c7c7f99bee9f65c7 Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Wed, 22 Sep 2010 13:05:09 -0700 Subject: [PATCH] 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 Cc: Thomas Winischhofer Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/sis/sis_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c index 559bf1727a2..b52f8e4ef1f 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); -- 2.20.1