Commit b2b476f5 authored Jul 20, 2010 by Pawel Osciak Committed by Mauro Carvalho Chehab Sep 30, 2010

V4L/DVB: v4l: videobuf: prevent passing a NULL to dma_free_coherent()



When a driver that uses videobuf-dma-contig is used with the USERPTR
memory access method a kernel oops might happen: a NULL address may be
passed to dma_free_coherent(). This happens when an application calls
REQBUFS and then exits without queuing any buffers. This patch fixes
that bug.

Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent a08c7c68

drivers/media/video/videobuf-dma-contig.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -393,9 +393,11 @@ void videobuf_dma_contig_free(struct videobuf_queue *q,
		}

		/* read() method */
		if (mem->vaddr) {
		dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
		mem->vaddr = NULL;
		}
		}
		EXPORT_SYMBOL_GPL(videobuf_dma_contig_free);

		MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers");