From: Tuo Li Date: Fri, 6 Aug 2021 13:30:29 +0000 (-0700) Subject: IB/hfi1: Fix possible null-pointer dereference in _extend_sdma_tx_descs() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fc5d2ff5d265a075b79224b2b48eec33845e5ab5;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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: 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 Signed-off-by: Sasha Levin --- diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index 76e63c88a87a..e9313e6f4b0e 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -3028,6 +3028,7 @@ 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)))) { @@ -3048,12 +3049,10 @@ 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;