Commit 48568005 authored May 27, 2010 by Julia Lawall Committed by Dan Williams Jul 01, 2010

drivers/dma: Eliminate a NULL pointer dereference

If td_desc is NULL, just skip both kfrees.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E == NULL && ...) || ...)
{
  ... when != if (...) S1 else S2
      when != E = E1
* E->f
  ... when any
  return ...;
}
else S3
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent efcc2898

drivers/dma/timb_dma.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -382,7 +382,7 @@ static struct timb_dma_desc td_alloc_init_desc(struct timb_dma_chan td_chan)
		td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
		if (!td_desc) {
		dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
		goto err;
		goto out;
		}

		td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
		@@ -410,7 +410,7 @@ static struct timb_dma_desc td_alloc_init_desc(struct timb_dma_chan td_chan)
		err:
		kfree(td_desc->desc_list);
		kfree(td_desc);

		out:
		return NULL;

		}

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