| Message ID | b80719f3-cff2-89f2-3ad1-d8e708808dbd@xs4all.nl (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for,5.18] v4l2-compat-ioctl32.c: zero buffer passed to v4l2_compat_get_array_args() | expand |
On 21/03/2022 09:33, Hans Verkuil wrote: > 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 Fixes: 8dbcc3fa387c (media: v4l2: prepare compat-ioctl rework) > --- > diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > index 0f3d6b5667b0..55c26e7d370e 100644 > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > @@ -1040,6 +1040,8 @@ 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:
Hi Hans, Thank you for the patch. On Mon, Mar 21, 2022 at 09:33:56AM +0100, Hans Verkuil wrote: > 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> > --- > diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > index 0f3d6b5667b0..55c26e7d370e 100644 > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > @@ -1040,6 +1040,8 @@ 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:
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 0f3d6b5667b0..55c26e7d370e 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -1040,6 +1040,8 @@ 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:
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 ---