Hi Laurent
On Wed, Mar 10, 2021 at 8:49 AM Laurent Pinchart laurent.pinchart@ideasonboard.com wrote:
Hi Ricardo,
Thank you for the patch.
Thank you!
On Wed, Mar 10, 2021 at 12:43:17AM +0100, Ricardo Ribalda wrote:
The plane_length is an unsigned integer. So, if we have a size of 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.
Cc: stable@vger.kernel.org Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") Signed-off-by: Ricardo Ribalda ribalda@chromium.org
drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 02281d13505f..543da515c761 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) * NOTE: mmapped areas should be page aligned */ for (plane = 0; plane < vb->num_planes; ++plane) {
unsigned long size = vb->planes[plane].length;unsigned long is still 32-bit on 32-bit platforms.
/* Memops alloc requires size to be page aligned. */
unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
size = PAGE_ALIGN(size); /* Did it wrap around? */ if (size < vb->planes[plane].length)Doesn't this address the issue already ?
Yes and no. If you need to allocate 0xffffffff you are still affected by the underrun. The core will return an error instead of doing the allocation.
(yes, I know it is a lot of memory for a buffer)
-- Regards,
Laurent Pinchart