From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34611 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753906AbbLKUVv (ORCPT ); Fri, 11 Dec 2015 15:21:51 -0500 Subject: Patch "RDS: fix race condition when sending a message on unbound socket" has been added to the 4.1-stable tree To: quentin.casasnovas@oracle.com, davem@davemloft.net, gregkh@linuxfoundation.org, santosh.shilimkar@oracle.com, sasha.levin@oracle.com, vegard.nossum@oracle.com Cc: , From: Date: Fri, 11 Dec 2015 08:48:53 -0800 Message-ID: <144985253342225@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled RDS: fix race condition when sending a message on unbound socket to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rds-fix-race-condition-when-sending-a-message-on-unbound-socket.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Fri Dec 11 11:39:13 EST 2015 From: Quentin Casasnovas Date: Tue, 24 Nov 2015 17:13:21 -0500 Subject: RDS: fix race condition when sending a message on unbound socket From: Quentin Casasnovas [ Upstream commit 8c7188b23474cca017b3ef354c4a58456f68303a ] Sasha's found a NULL pointer dereference in the RDS connection code when sending a message to an apparently unbound socket. The problem is caused by the code checking if the socket is bound in rds_sendmsg(), which checks the rs_bound_addr field without taking a lock on the socket. This opens a race where rs_bound_addr is temporarily set but where the transport is not in rds_bind(), leading to a NULL pointer dereference when trying to dereference 'trans' in __rds_conn_create(). Vegard wrote a reproducer for this issue, so kindly ask him to share if you're interested. I cannot reproduce the NULL pointer dereference using Vegard's reproducer with this patch, whereas I could without. Complete earlier incomplete fix to CVE-2015-6937: 74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection") Cc: David S. Miller Cc: stable@vger.kernel.org Reviewed-by: Vegard Nossum Reviewed-by: Sasha Levin Acked-by: Santosh Shilimkar Signed-off-by: Quentin Casasnovas Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/connection.c | 6 ------ net/rds/send.c | 4 +++- 2 files changed, 3 insertions(+), 7 deletions(-) --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -187,12 +187,6 @@ new_conn: } } - if (trans == NULL) { - kmem_cache_free(rds_conn_slab, conn); - conn = ERR_PTR(-ENODEV); - goto out; - } - conn->c_trans = trans; ret = trans->conn_alloc(conn, gfp); --- a/net/rds/send.c +++ b/net/rds/send.c @@ -986,11 +986,13 @@ int rds_sendmsg(struct socket *sock, str release_sock(sk); } - /* racing with another thread binding seems ok here */ + lock_sock(sk); if (daddr == 0 || rs->rs_bound_addr == 0) { + release_sock(sk); ret = -ENOTCONN; /* XXX not a great errno */ goto out; } + release_sock(sk); /* size of rm including all sgs */ ret = rds_rm_size(msg, payload_len); Patches currently in stable-queue which might be from quentin.casasnovas@oracle.com are queue-4.1/rds-fix-race-condition-when-sending-a-message-on-unbound-socket.patch