[PATCH 5.13 040/113] RDMA/rxe: Fix memory allocation while in a spin lock

From: Greg Kroah-Hartman
Date: Wed Sep 01 2021 - 08:48:24 EST


From: Bob Pearson <rpearsonhpe@xxxxxxxxx>

[ Upstream commit 65a81b61d8c5e96748671824cc46339afbd831d0 ]

rxe_mcast_add_grp_elem() in rxe_mcast.c calls rxe_alloc() while holding
spinlocks which in turn calls kzalloc(size, GFP_KERNEL) which is
incorrect. This patch replaces rxe_alloc() by rxe_alloc_locked() which
uses GFP_ATOMIC. This bug was caused by the below mentioned commit and
failing to handle the need for the atomic allocate.

Fixes: 4276fd0dddc9 ("RDMA/rxe: Remove RXE_POOL_ATOMIC")
Link: https://lore.kernel.org/r/20210813210625.4484-1-rpearsonhpe@xxxxxxxxx
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_mcast.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_mcast.c b/drivers/infiniband/sw/rxe/rxe_mcast.c
index 0ea9a5aa4ec0..1c1d1b53312d 100644
--- a/drivers/infiniband/sw/rxe/rxe_mcast.c
+++ b/drivers/infiniband/sw/rxe/rxe_mcast.c
@@ -85,7 +85,7 @@ int rxe_mcast_add_grp_elem(struct rxe_dev *rxe, struct rxe_qp *qp,
goto out;
}

- elem = rxe_alloc(&rxe->mc_elem_pool);
+ elem = rxe_alloc_locked(&rxe->mc_elem_pool);
if (!elem) {
err = -ENOMEM;
goto out;
--
2.30.2