From: Pawel Osciak <[email protected]>

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 <[email protected]>
Signed-off-by: Kyungmin Park <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
 drivers/media/video/videobuf-dma-contig.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/video/videobuf-dma-contig.c 
b/drivers/media/video/videobuf-dma-contig.c
index 372b87e..6ff9e4b 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -393,8 +393,10 @@ void videobuf_dma_contig_free(struct videobuf_queue *q,
        }
 
        /* read() method */
-       dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
-       mem->vaddr = NULL;
+       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);
 
-- 
1.7.2.2

--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to