[PATCH] dmaengine: ti: edma: Fix memory allocation size for queue_priority_map
From: Anders Roxell
Date: Fri Aug 29 2025 - 09:18:01 EST
Fix a critical memory allocation bug in edma_setup_from_hw() where
queue_priority_map was allocated with insufficient memory. The code
declared queue_priority_map as s8 (*)[2] (pointer to array of 2 s8), but
allocated memory using sizeof(s8) instead of sizeof(s8[2]).
This caused out-of-bounds memory writes when accessing:
queue_priority_map[i][0] = i;
queue_priority_map[i][1] = i;
The bug manifested as kernel crashes with "Oops - undefined instruction"
on ARM platforms (BeagleBoard-X15) during EDMA driver probe, as the
memory corruption triggered kernel hardening features on Clang.
Change the allocation from:
devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8), GFP_KERNEL)
to this:
devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8[2]), GFP_KERNEL)
This ensures proper allocation of (ecc->num_tc + 1) * 2 bytes to match
the expected 2D array structure.
Fixes: 2b6b3b742019 ("ARM/dmaengine: edma: Merge the two drivers under drivers/dma/")
Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
---
drivers/dma/ti/edma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
index 3ed406f08c44..8f9b65e4bc87 100644
--- a/drivers/dma/ti/edma.c
+++ b/drivers/dma/ti/edma.c
@@ -2064,7 +2064,7 @@ static int edma_setup_from_hw(struct device *dev, struct edma_soc_info *pdata,
* priority. So Q0 is the highest priority queue and the last queue has
* the lowest priority.
*/
- queue_priority_map = devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8),
+ queue_priority_map = devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8[2]),
GFP_KERNEL);
if (!queue_priority_map)
return -ENOMEM;
--
2.50.1