[PATCH v3 2/4] dmaengine: dw-axi-dmac: Fix LLI dump out-of-bounds access

[Jia Wang]

axi_chan_list_dump_lli() uses the channel-wide descs_allocated count to
walk the hw_desc[] array of a single transaction. If multiple
transactions have allocated LLIs, the channel count can exceed the
transaction-local nr_hw_descs and make the DMA error path read past the
end of hw_desc[].

Use the descriptor-local nr_hw_descs count when dumping LLIs.

Fixes: ef6fb2d6f1ab ("dmaengine: dw-axi-dmac: simplify descriptor management")
Signed-off-by: Jia Wang <wangjia@xxxxxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

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 742e08cfab43..61230d2b1c56 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -1052,10 +1052,7 @@ static void axi_chan_dump_lli(struct axi_dma_chan *chan,
 static void axi_chan_list_dump_lli(struct axi_dma_chan *chan,
 				   struct axi_dma_desc *desc_head)
 {
-	int count = atomic_read(&chan->descs_allocated);
-	int i;
-
-	for (i = 0; i < count; i++)
+	for (unsigned int i = 0; i < desc_head->nr_hw_descs; i++)
 		axi_chan_dump_lli(chan, &desc_head->hw_desc[i]);
 }
 

-- 
2.34.1