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authorNicolas Ferre <nicolas.ferre@atmel.com>2012-09-11 17:21:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-02 09:47:37 -0700
commite24fd5136ca6d256900392565dfc895d5a2ed9b2 (patch)
tree59b589583329e2291cf593f24681d2674bda71a6 /drivers/dma
parent5b77c2c77ade979204e5c6915c61e1d6196f70c5 (diff)
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dmaengine: at_hdmac: check that each sg data length is non-null
commit c456797681db814f4f5b36909e8e94047bf53d9c upstream. Avoid the construction of a malformed DMA request sent to the DMA controller. Log message is for debug only because this condition is unlikely to append and may only trigger at driver development time. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/at_hdmac.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index fcccbdf..1357c3b 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -702,6 +702,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
@@ -736,6 +741,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
@@ -769,6 +779,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
err_desc_get:
dev_err(chan2dev(chan), "not enough descriptors available\n");
+err:
atc_desc_put(atchan, first);
return NULL;
}