From cbe71c61992c38f72c2b625b2ef25916b9f0d060 Mon Sep 17 00:00:00 2001 From: Tuo Li Date: Fri, 6 Aug 2021 06:30:29 -0700 Subject: 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: 7724105686e7 ("IB/hfi1: add driver files") Link: https://lore.kernel.org/r/20210806133029.194964-1-islituo@gmail.com Reported-by: TOTE Robot Signed-off-by: Tuo Li Tested-by: Mike Marciniszyn Acked-by: Mike Marciniszyn Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/hfi1/sdma.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index eb15c310d63d..e83dc562629e 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -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; -- cgit