[PATCH v2] media: videobuf2: Fix integer overrun in vb2_mmap

[Ricardo Ribalda]

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.

Suggested-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 543da515c761..89c8bacb94a7 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2256,7 +2256,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
 	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
 	 * so, we need to do the same here.
 	 */
-	length = PAGE_ALIGN(vb->planes[plane].length);
+	length = PAGE_ALIGN((unsigned long)vb->planes[plane].length);
 	if (length < (vma->vm_end - vma->vm_start)) {
 		dprintk(q, 1,
 			"MMAP invalid, as it would overflow buffer length\n");
-- 
2.30.1.766.gb4fecdf3b7-goog