Commit 8a21e843 authored Aug 06, 2021 by Tuo Li Committed by Greg Kroah-Hartman Sep 03, 2021

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

[ Upstream commit cbe71c61992c38f72c2b625b2ef25916b9f0d060 ]

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: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
Tested-by: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Acked-by: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 944a50f5

drivers/infiniband/hw/hfi1/sdma.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -3056,6 +3056,7 @@ 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)))) {
		@@ -3076,12 +3077,10 @@ 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;