Messages in this thread Patch in this message |  | | | Date | Tue, 07 Dec 2010 16:04:40 -0800 | | From | Greg KH <> | | Subject | [41/44] V4L/DVB: ivtvfb: prevent reading uninitialized stack memory |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------ From: Dan Rosenberg <drosenberg@vsecurity.com>
commit 405707985594169cfd0b1d97d29fcb4b4c6f2ac9 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> Signed-off-by: Andy Walls <awalls@md.metrocast.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/media/video/ivtv/ivtvfb.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/media/video/ivtv/ivtvfb.c +++ b/drivers/media/video/ivtv/ivtvfb.c @@ -460,6 +460,8 @@ static int ivtvfb_ioctl(struct fb_info * struct fb_vblank vblank; u32 trace; + memset(&vblank, 0, sizeof(struct fb_vblank)); + vblank.flags = FB_VBLANK_HAVE_COUNT |FB_VBLANK_HAVE_VCOUNT | FB_VBLANK_HAVE_VSYNC; trace = read_reg(0x028c0) >> 16;
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