Hi Mauro,
Thank you for the patch.
On Wed, Sep 02, 2020 at 06:10:05PM +0200, Mauro Carvalho Chehab wrote:
> There are some reports about possible memory leaks:
>
> drivers/media/v4l2-core//v4l2-ioctl.c:3203 video_put_user() warn: check
> that 'ev32' doesn't leak information (struct has a hole after 'type')
> drivers/media/v4l2-core//v4l2-ioctl.c:3230 video_put_user() warn: check
> that 'vb32' doesn't leak information (struct has a hole after 'memory')
>
> While smatch seems to be reporting a false positive (line 3203),
> there's indeed a possible leak with reserved2 at vb32.
>
> We might have fixed just that one, but smatch checks won't
> be able to check leaks at ev32. So, re-work the code in a way
> that will ensure that the var contents will be zeroed before
> filling it.
>
> With that, we don't need anymore to touch reserved fields.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>
> ---
> drivers/media/v4l2-core/v4l2-ioctl.c | 48 ++++++++++++++--------------
> 1 file changed, 24 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
> b/drivers/media/v4l2-core/v4l2-ioctl.c
> index a556880f225a..6f3fe9c4b64a 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -3189,17 +3189,16 @@ static int video_put_user(void __user *arg, void
> *parg, unsigned int cmd)
> #ifdef CONFIG_COMPAT_32BIT_TIME
> case VIDIOC_DQEVENT_TIME32: {
> struct v4l2_event *ev = parg;
> - struct v4l2_event_time32 ev32 = {
> - .type = ev->type,
> - .pending = ev->pending,
> - .sequence = ev->sequence,
> - .timestamp.tv_sec = ev->timestamp.tv_sec,
> - .timestamp.tv_nsec = ev->timestamp.tv_nsec,
> - .id = ev->id,
> - };
> + struct v4l2_event_time32 ev32;
>
> + memset(&ev32, 0, sizeof(ev32));
> + ev32.type = ev->type,
The lines should end with ';', not ','.
With this fixed,
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> + ev32.pending = ev->pending,
> + ev32.sequence = ev->sequence,
> + ev32.timestamp.tv_sec = ev->timestamp.tv_sec,
> + ev32.timestamp.tv_nsec = ev->timestamp.tv_nsec,
> + ev32.id = ev->id,
> memcpy(&ev32.u, &ev->u, sizeof(ev->u));
> - memcpy(&ev32.reserved, &ev->reserved, sizeof(ev->reserved));
>
> if (copy_to_user(arg, &ev32, sizeof(ev32)))
> return -EFAULT;
> @@ -3210,21 +3209,22 @@ static int video_put_user(void __user *arg, void
> *parg, unsigned int cmd)
> case VIDIOC_DQBUF_TIME32:
> case VIDIOC_PREPARE_BUF_TIME32: {
> struct v4l2_buffer *vb = parg;
> - struct v4l2_buffer_time32 vb32 = {
> - .index = vb->index,
> - .type = vb->type,
> - .bytesused = vb->bytesused,
> - .flags = vb->flags,
> - .field = vb->field,
> - .timestamp.tv_sec = vb->timestamp.tv_sec,
> - .timestamp.tv_usec = vb->timestamp.tv_usec,
> - .timecode = vb->timecode,
> - .sequence = vb->sequence,
> - .memory = vb->memory,
> - .m.userptr = vb->m.userptr,
> - .length = vb->length,
> - .request_fd = vb->request_fd,
> - };
> + struct v4l2_buffer_time32 vb32;
> +
> + memset(&vb32, 0, sizeof(vb32));
> + vb32.index = vb->index,
> + vb32.type = vb->type,
> + vb32.bytesused = vb->bytesused,
> + vb32.flags = vb->flags,
> + vb32.field = vb->field,
> + vb32.timestamp.tv_sec = vb->timestamp.tv_sec,
> + vb32.timestamp.tv_usec = vb->timestamp.tv_usec,
> + vb32.timecode = vb->timecode,
> + vb32.sequence = vb->sequence,
> + vb32.memory = vb->memory,
> + vb32.length = vb->length,
> + vb32.request_fd = vb->request_fd,
> + memcpy(&vb32.m, &vb->m, sizeof(vb->m));
>
> if (copy_to_user(arg, &vb32, sizeof(vb32)))
> return -EFAULT;
--
Regards,
Laurent Pinchart
