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

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: 1fe20f1b84 ("dmaengine: Introduce DW AXI DMAC driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Colin Ian King 2019-05-08 23:33:29 +01:00 committed by Vinod Koul
parent 827484912e
commit 0788611c9a

View File

@ -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;
}