Re: [PATCH v3 03/11] media: videobuf2: Remove VB2_MAX_FRAME limit on buffer storage

Dan Carpenter
2023-06-22T14:11:33Z

On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index f1ff7af34a9f..86e1e926fa45 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> struct vb2_buffer *vb;
> int ret;
>
> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
> num_buffers = min_t(unsigned int, num_buffers,
> - VB2_MAX_FRAME - q->num_buffers);
> + UINT_MAX - q->num_buffers);
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */

Ah... Here's one of the integer overflow bugs I was talking about. The
__vb2_queue_alloc() function returns an int so if num_buffers goes over
INT_MAX we are hosed.

regards,
dan carpenter