media: videobuf2-dma-sg: Prevent size from overflowing

commit 14f28f5cea9e3998442de87846d1907a531b6748 upstream.

buf->size is an unsigned long; casting that to int will lead to an
overflow if buf->size exceeds INT_MAX.

Fix this by changing the type to unsigned long instead. This is possible
as the buf->size is always aligned to PAGE_SIZE, and therefore the size
will never have values lesser than 0.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 270c3162fdcb3fd150cd414757028fbbe0500234..61670a1af71399302ed7472b2f8f6039771451db 100644 (file)
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -59,7 +59,7 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
                gfp_t gfp_flags)
 {
        unsigned int last_page = 0;
-       int size = buf->size;
+       unsigned long size = buf->size;
 
        while (size > 0) {
                struct page *pages;