From: Mohamed Ghannam <simo.ghannam@gmail.com>
Date: Wed, 3 Jan 2018 21:06:06 +0000
Subject: RDS: null pointer dereference in rds_atomic_free_op
Patch-mainline: v4.15-rc8
Git-commit: 7d11f77f84b27cef452cee332f4e469503084737
References: CVE-2018-5333 bsc#1075617

set rm->atomic.op_active to 0 when rds_pin_pages() fails
or the user supplied address is invalid,
this prevents a NULL pointer usage in rds_atomic_free_op()

Signed-off-by: Mohamed Ghannam <simo.ghannam@gmail.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>

---
 net/rds/rdma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index f06fac4886b0..34168ee2a8df 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -874,6 +874,7 @@ int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
 err:
 	if (page)
 		put_page(page);
+	rm->atomic.op_active = 0;
 	kfree(rm->atomic.op_notifier);
 
 	return ret;
-- 
2.16.0