[PATCH] media: videobuf2: Fix integer overrun in allocation

[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.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
 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;
+
 		/* 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)
-- 
2.30.1.766.gb4fecdf3b7-goog