net/rds: An rds_sock is added too early to the hash table

In rds_bind(), an rds_sock is added to the RDS bind hash table before
rs_transport is set.  This means that the socket can be found by the
receive code path when rs_transport is NULL.  And the receive code
path de-references rs_transport for congestion update check.  This can
cause a panic.  An rds_sock should not be added to the bind hash table
before all the needed fields are set.

Reported-by: syzbot+4b4f8163c2e246df3c4c@syzkaller.appspotmail.com
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ka-Cheong Poon 2019-09-11 02:58:05 -07:00 committed by David S. Miller
parent 3e493173b7
commit c5c1a030a7

View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2006, 2019 Oracle and/or its affiliates. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
@ -239,34 +239,30 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
goto out;
}
sock_set_flag(sk, SOCK_RCU_FREE);
ret = rds_add_bound(rs, binding_addr, &port, scope_id);
if (ret)
goto out;
if (rs->rs_transport) { /* previously bound */
/* The transport can be set using SO_RDS_TRANSPORT option before the
* socket is bound.
*/
if (rs->rs_transport) {
trans = rs->rs_transport;
if (trans->laddr_check(sock_net(sock->sk),
binding_addr, scope_id) != 0) {
ret = -ENOPROTOOPT;
rds_remove_bound(rs);
} else {
ret = 0;
goto out;
}
goto out;
}
trans = rds_trans_get_preferred(sock_net(sock->sk), binding_addr,
scope_id);
if (!trans) {
ret = -EADDRNOTAVAIL;
rds_remove_bound(rs);
pr_info_ratelimited("RDS: %s could not find a transport for %pI6c, load rds_tcp or rds_rdma?\n",
__func__, binding_addr);
goto out;
} else {
trans = rds_trans_get_preferred(sock_net(sock->sk),
binding_addr, scope_id);
if (!trans) {
ret = -EADDRNOTAVAIL;
pr_info_ratelimited("RDS: %s could not find a transport for %pI6c, load rds_tcp or rds_rdma?\n",
__func__, binding_addr);
goto out;
}
rs->rs_transport = trans;
}
rs->rs_transport = trans;
ret = 0;
sock_set_flag(sk, SOCK_RCU_FREE);
ret = rds_add_bound(rs, binding_addr, &port, scope_id);
out:
release_sock(sk);