RDMA: Fix use-after-free in rxe_queue_cleanup

[ Upstream commit 84b01721e8042cdd1e8ffeb648844a09cd4213e0 ]

On error handling path in rxe_qp_from_init() qp->sq.queue is freed and
then rxe_create_qp() will drop last reference to this object. qp clean up
function will try to free this queue one time and it causes UAF bug.

Fix it by zeroing queue pointer after freeing queue in rxe_qp_from_init().

Fixes: 514aee660df4 ("RDMA: Globally allocate and release QP memory")
Link: https://lore.kernel.org/r/20211121202239.3129-1-paskripkin@gmail.com
Reported-by: syzbot+aab53008a5adf26abe91@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
index 1ab6af7ddb2549c7e28409169041ee40b9387526..ed326d82725cd1af5587954ba3557a455ca59daa 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -367,6 +367,7 @@ int rxe_qp_from_init(struct rxe_dev *rxe, struct rxe_qp *qp, struct rxe_pd *pd,
 
 err2:
        rxe_queue_cleanup(qp->sq.queue);
+       qp->sq.queue = NULL;
 err1:
        qp->pd = NULL;
        qp->rcq = NULL;