There are two place if the at_xdmac_interleaved_queue_desc() fails which
could lead to a NULL dereference where "first" is NULL and we call
list_add_tail(&first->desc_node, ...). In the first caller, the return
is not checked so add a check for that. In the next caller, the return
is checked but if it fails on the first iteration through the loop then
it will lead to a NULL pointer dereference.
Fixes: 4e5385784e69 ("dmaengine: at_xdmac: handle numf > 1")
Fixes: 62b5cb757f1d ("dmaengine: at_xdmac: fix memory leak in interleaved mode")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/dma/at_xdmac.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 7da6d9b6098e..c3b37168b21f 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1102,6 +1102,8 @@ at_xdmac_prep_interleaved(struct dma_chan *chan,
NULL,
src_addr, dst_addr,
xt, xt->sgl);
+ if (!first)
+ return NULL;
/* Length of the block is (BLEN+1) microblocks. */
for (i = 0; i < xt->numf - 1; i++)
@@ -1132,8 +1134,9 @@ at_xdmac_prep_interleaved(struct dma_chan *chan,
src_addr, dst_addr,
xt, chunk);
if (!desc) {
- list_splice_tail_init(&first->descs_list,
- &atchan->free_descs_list);
+ if (first)
+ list_splice_tail_init(&first->descs_list,
+ &atchan->free_descs_list);
return NULL;
}
--
2.39.2
