From: Pavel Skripkin <paskripkin@gmail.com>
Date: Sun, 21 Nov 2021 23:22:39 +0300
Subject: RDMA: Fix use-after-free in rxe_queue_cleanup
Patch-mainline: v5.16-rc5
Git-commit: 84b01721e8042cdd1e8ffeb648844a09cd4213e0
References: jsc#SLE-19249

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/sw/rxe/rxe_qp.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -359,6 +359,7 @@ int rxe_qp_from_init(struct rxe_dev *rxe
 
 err2:
 	rxe_queue_cleanup(qp->sq.queue);
+	qp->sq.queue = NULL;
 err1:
 	qp->pd = NULL;
 	qp->rcq = NULL;