media: v4l2-compat-ioctl32.c: zero buffer passed to v4l2_compat_get_array_args()

commit 4e768c8e34e639cff66a0f175bc4aebf472e4305 upstream.

The v4l2_compat_get_array_args() function can leave uninitialized memory in the
buffer it is passed. So zero it before copying array elements from userspace
into the buffer.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: syzbot+ff18193ff05f3f87f226@syzkaller.appspotmail.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 80aaf07b16f2827e56c71daa27b77dd0acc5221e..94037af1af2dc37eee747222187a978a3159f7b3 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -1033,6 +1033,8 @@ int v4l2_compat_get_array_args(struct file *file, void *mbuf,
 {
        int err = 0;
 
+       memset(mbuf, 0, array_size);
+
        switch (cmd) {
        case VIDIOC_G_FMT32:
        case VIDIOC_S_FMT32: