media: videobuf2-core: Prevent size alignment wrapping buffer size to 0

PAGE_ALIGN() may wrap the buffer size around to 0. Prevent this by
checking that the aligned value is not smaller than the unaligned one.

Note on backporting to stable: the file used to be under
drivers/media/v4l2-core, it was moved to the current location after 4.14.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 3cf25ab..cfccee8 100644 (file)
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -207,6 +207,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
        for (plane = 0; plane < vb->num_planes; ++plane) {
                unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 
+               /* Did it wrap around? */
+               if (size < vb->planes[plane].length)
+                       goto free;
+
                mem_priv = call_ptr_memop(vb, alloc,
                                q->alloc_devs[plane] ? : q->dev,
                                q->dma_attrs, size, q->dma_dir, q->gfp_flags);