If the dw_edma_alloc_burst() function fails then we free "chunk" but
it's still on the "desc->chunk->list" list so it will lead to a use
after free. Also the "->chunks_alloc" count is incremented when it
shouldn't be.
In current kernels small allocations are guaranteed to succeed and
dw_edma_alloc_burst() can't fail so this will not actually affect
runtime.
Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
Based on static analysis. Not tested.
drivers/dma/dw-edma/dw-edma-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index b971505b8715..08d71dafa001 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -86,12 +86,12 @@ static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc)
if (desc->chunk) {
/* Create and add new element into the linked list */
- desc->chunks_alloc++;
- list_add_tail(&chunk->list, &desc->chunk->list);
if (!dw_edma_alloc_burst(chunk)) {
kfree(chunk);
return NULL;
}
+ desc->chunks_alloc++;
+ list_add_tail(&chunk->list, &desc->chunk->list);
} else {
/* List head */
chunk->burst = NULL;
--
2.29.2
