From: Tuo Li islituo@gmail.com
[ 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: 7724105686e7 ("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 --- 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 291c12f588b5..38258de75a94 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;