From: Dan Rosenberg <[email protected]> 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 <[email protected]> Cc: Thomas Winischhofer <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- drivers/video/sis/sis_main.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c index a531a0f..900b3a0 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); -- 1.7.3.3 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
