diff mbox series

dma: dw-axi-dmac: fix null dereference when pointer first is null

Message ID 20190508223329.26796-1-colin.king@canonical.com (mailing list archive)
State Accepted
Headers show
Series dma: dw-axi-dmac: fix null dereference when pointer first is null | expand

Commit Message

Colin King May 8, 2019, 10:33 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

In the unlikely event that axi_desc_get returns a null desc in the
very first iteration of the while-loop the error exit path ends
up calling axi_desc_put on a null pointer 'first' and this causes
a null pointer dereference.  Fix this by adding a null check on
pointer 'first' before calling axi_desc_put.

Addresses-Coverity: ("Explicit null dereference")
fixes: 1fe20f1b8454 ("dmaengine: Introduce DW AXI DMAC driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Vinod Koul May 21, 2019, 4:57 a.m. UTC | #1 
On 08-05-19, 23:33, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> In the unlikely event that axi_desc_get returns a null desc in the
> very first iteration of the while-loop the error exit path ends
> up calling axi_desc_put on a null pointer 'first' and this causes
> a null pointer dereference.  Fix this by adding a null check on
> pointer 'first' before calling axi_desc_put.

Applied, thanks
diff mbox series

Patch

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index b2ac1d2c5b86..a1ce307c502f 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -512,7 +512,8 @@  dma_chan_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dst_adr,
 	return vchan_tx_prep(&chan->vc, &first->vd, flags);
 
 err_desc_get:
-	axi_desc_put(first);
+	if (first)
+		axi_desc_put(first);
 	return NULL;
 }