[PATCH AUTOSEL 4.19 02/39] dmaengine: dw-axi-dmac: fix null dereference when pointer first is null

[PATCH AUTOSEL 4.19 02/39] dmaengine: dw-axi-dmac: fix null dereference when pointer first is null

[Sasha Levin]

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 0788611c9a0925c607de536b2449de5ed98ef8df ]

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>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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 c4eb55e3011c..c05ef7f1d7b6 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;
 }
 
-- 
2.20.1

[PATCH AUTOSEL 4.19 03/39] dmaengine: sprd: Fix block length overflow

[Sasha Levin]

From: Eric Long <eric.long@unisoc.com>

[ Upstream commit 89d03b3c126d683f7b2cd5b07178493993d12448 ]

The maximum value of block length is 0xffff, so if the configured transfer length
is more than 0xffff, that will cause block length overflow to lead a configuration
error.

Thus we can set block length as the maximum burst length to avoid this issue, since
the maximum burst length will not be a big value which is more than 0xffff.

Signed-off-by: Eric Long <eric.long@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/sprd-dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 55df0d41355b..1ed1c7efa288 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -663,7 +663,7 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
 	temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
 	hw->frg_len = temp;
 
-	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
+	hw->blk_len = slave_cfg->src_maxburst & SPRD_DMA_BLK_LEN_MASK;
 	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
 
 	temp = (dst_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
-- 
2.20.1