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Subject[PATCH 5/11] drivers/dma: Eliminate a NULL pointer dereference
From: Julia Lawall <julia@diku.dk>

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>

---
drivers/dma/timb_dma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/timb_dma.c b/drivers/dma/timb_dma.c
index 0172fa3..c4eb96a 100644
--- a/drivers/dma/timb_dma.c
+++ b/drivers/dma/timb_dma.c
@@ -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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