Commit cbe71c61 authored by Tuo Li's avatar Tuo Li Committed by Jason Gunthorpe
Browse files

IB/hfi1: Fix possible null-pointer dereference in _extend_sdma_tx_descs() 

kmalloc_array() is called to allocate memory for tx->descp. If it fails,
the function __sdma_txclean() is called:
  __sdma_txclean(dd, tx);

However, in the function __sdma_txclean(), tx-descp is dereferenced if
tx->num_desc is not zero:
  sdma_unmap_desc(dd, &tx->descp[0]);

To fix this possible null-pointer dereference, assign the return value of
kmalloc_array() to a local variable descp, and then assign it to tx->descp
if it is not NULL. Otherwise, go to enomem.

Fixes: 77241056 ("IB/hfi1: add driver files")
Link: https://lore.kernel.org/r/20210806133029.194964-1-islituo@gmail.com


Reported-by: default avatarTOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: default avatarTuo Li <islituo@gmail.com>
Tested-by: default avatarMike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Acked-by: default avatarMike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 00326402

drivers/infiniband/hw/hfi1/sdma.c

+4 −5
Original line number Diff line number Diff line
@@ -3055,6 +3055,7 @@ static void __sdma_process_event(struct sdma_engine *sde, 
static int _extend_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)

{

	int i;

	struct sdma_desc *descp;



	/* Handle last descriptor */

	if (unlikely((tx->num_desc == (MAX_DESC - 1)))) {
@@ -3075,12 +3076,10 @@ static int _extend_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx) 
	if (unlikely(tx->num_desc == MAX_DESC))

		goto enomem;



	tx->descp = kmalloc_array(

			MAX_DESC,

			sizeof(struct sdma_desc),

			GFP_ATOMIC);

	if (!tx->descp)

	descp = kmalloc_array(MAX_DESC, sizeof(struct sdma_desc), GFP_ATOMIC);

	if (!descp)

		goto enomem;

	tx->descp = descp;



	/* reserve last descriptor for coalescing */

	tx->desc_limit = MAX_DESC - 1;