From: Pawel Osciak <p.osciak@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
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
--
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