From c5c1a030a7dbf8dd4e1fa4405ae9a89dc1d2a8db Mon Sep 17 00:00:00 2001 From: Ka-Cheong Poon Date: Wed, 11 Sep 2019 02:58:05 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/rds/bind.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/net/rds/bind.c b/net/rds/bind.c index 0f4398e7f2a7..05464fd7c17a 100644 --- a/net/rds/bind.c +++ b/net/rds/bind.c @@ -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);