Commit c5c1a030 authored by Ka-Cheong Poon's avatar Ka-Cheong Poon Committed by David S. Miller
Browse files

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: default avatar <syzbot+4b4f8163c2e246df3c4c@syzkaller.appspotmail.com>
Signed-off-by: default avatarKa-Cheong Poon <ka-cheong.poon@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3e493173

net/rds/bind.c

+18 −22
Original line number Diff line number Diff line 
/*

 * 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;

		}

	trans = rds_trans_get_preferred(sock_net(sock->sk), binding_addr,

					scope_id);

	} else {

		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;

		}



		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);

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