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authorPawel Osciak <p.osciak@samsung.com>2010-07-20 13:49:16 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-09-30 07:22:22 -0300
commitb2b476f53a9d24b00a313adf7f6ca92515a2af54 (patch)
tree4510939190c507264aa46623daec039f703f9fbd
parenta08c7c68f702e2a2797a4035b6c0a756c4886c26 (diff)
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>
-rw-r--r--drivers/media/video/videobuf-dma-contig.c6
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 372b87efcd05..6ff9e4bac3ea 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);