[PATCH net-next] net/rds: Check laddr_check before calling it

[Ka-Cheong Poon]

In rds_bind(), laddr_check is called without checking if it is NULL or
not.  And rs_transport should be reset if rds_add_bound() fails.

Fixes: c5c1a030a7db ("net/rds: Check laddr_check before calling it")
Reported-by: syzbot+fae39afd2101a17ec...@syzkaller.appspotmail.com
Signed-off-by: Ka-Cheong Poon <ka-cheong.p...@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilim...@oracle.com>
---
 net/rds/bind.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 20c156a..5b5fb4c 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -244,7 +244,8 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, 
int addr_len)
         */
        if (rs->rs_transport) {
                trans = rs->rs_transport;
-               if (trans->laddr_check(sock_net(sock->sk),
+               if (!trans->laddr_check ||
+                   trans->laddr_check(sock_net(sock->sk),
                                       binding_addr, scope_id) != 0) {
                        ret = -ENOPROTOOPT;
                        goto out;
@@ -263,6 +264,8 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, 
int addr_len)
 
        sock_set_flag(sk, SOCK_RCU_FREE);
        ret = rds_add_bound(rs, binding_addr, &port, scope_id);
+       if (ret)
+               rs->rs_transport = NULL;
 
 out:
        release_sock(sk);
-- 
1.8.3.1