[PATCH 2/2] dmaengine: at_hdmac: check that each sg data length is non-null
From: Nicolas Ferre <hidden>
Date: 2012-09-11 15:22:21
Also in:
lkml
Subsystem:
dma generic offload engine subsystem, microchip at91 dma drivers, the rest · Maintainers:
Vinod Koul, Ludovic Desroches, Linus Torvalds
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 <redacted> Cc: Stable <redacted> [2.6.31+] --- drivers/dma/at_hdmac.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 6c09e18..7ab6e26 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c@@ -689,6 +689,11 @@ 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;
@@ -724,6 +729,11 @@ 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;
@@ -757,6 +767,7 @@ 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; }
--
1.7.10