This is a note to let you know that I've just added the patch titled
dmaengine: at_xdmac: fix potential Oops in at_xdmac_prep_interleaved()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-at_xdmac-fix-potential-oops-in-at_xdmac_pr.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 17a4d8f9948f2bcfa08f0c9b60e0c6ddff5a291f
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Mon May 15 13:32:10 2023 +0300
dmaengine: at_xdmac: fix potential Oops in at_xdmac_prep_interleaved()
[ Upstream commit 4d43acb145c363626d76f49febb4240c488cd1cf ]
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>
Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
Link: https://lore.kernel.org/r/21282b66-9860-410a-83df-39c17fcf2f1b@kili.mountain
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b45437aab1434..dd34626df1abc 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1026,6 +1026,8 @@ 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++)
@@ -1056,8 +1058,9 @@ 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;
}
