From b2b476f53a9d24b00a313adf7f6ca92515a2af54 Mon Sep 17 00:00:00 2001 From: Pawel Osciak Date: Tue, 20 Jul 2010 13:49:16 -0300 Subject: 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 Signed-off-by: Kyungmin Park Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf-dma-contig.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/media') 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); -- cgit v1.2.3