rds; Reset rs->rs_bound_addr in rds_add_bound() failure path

If the rds_sock is not added to the bind_hash_table, we must
reset rs_bound_addr so that rds_remove_bound will not trip on
this rds_sock.

rds_add_bound() does a rds_sock_put() in this failure path, so
failing to reset rs_bound_addr will result in a socket refcount
bug, and will trigger a WARN_ON with the stack shown below when
the application subsequently tries to close the PF_RDS socket.

     WARNING: CPU: 20 PID: 19499 at net/rds/af_rds.c:496 \
		rds_sock_destruct+0x15/0x30 [rds]
       :
     __sk_destruct+0x21/0x190
     rds_remove_bound.part.13+0xb6/0x140 [rds]
     rds_release+0x71/0x120 [rds]
     sock_release+0x1a/0x70
     sock_close+0xe/0x20
     __fput+0xd5/0x210
     task_work_run+0x82/0xa0
     do_exit+0x2ce/0xb30
     ? syscall_trace_enter+0x1cc/0x2b0
     do_group_exit+0x39/0xa0
     SyS_exit_group+0x10/0x10
     do_syscall_64+0x61/0x1a0

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 75d43dc8e96b4655becce35dcaa5dd570abf4a41..5aa3a64aa4f0ef254bd31ecbfb11c81db0438185 100644 (file)
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -114,6 +114,7 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
                          rs, &addr, (int)ntohs(*port));
                        break;
                } else {
+                       rs->rs_bound_addr = 0;
                        rds_sock_put(rs);
                        ret = -ENOMEM;
                        break;