From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966181AbcKNDzW (ORCPT ); Sun, 13 Nov 2016 22:55:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45084 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415AbcKNCEO (ORCPT ); Sun, 13 Nov 2016 21:04:14 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Steffen Klassert" , "Vegard Nossum" , "Nicolas Dichtel" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 080/346] xfrm: fix crash in XFRM_MSG_GETSA netlink handler In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Vegard Nossum commit 1ba5bf993c6a3142e18e68ea6452b347f9cb5635 upstream. If we hit any of the error conditions inside xfrm_dump_sa(), then xfrm_state_walk_init() never gets called. However, we still call xfrm_state_walk_done() from xfrm_dump_sa_done(), which will crash because the state walk was never initialized properly. We can fix this by setting cb->args[0] only after we've processed the first element and checking this before calling xfrm_state_walk_done(). Fixes: d3623099d3 ("ipsec: add support of limited SA dump") Cc: Nicolas Dichtel Cc: Steffen Klassert Signed-off-by: Vegard Nossum Acked-by: Nicolas Dichtel Signed-off-by: Steffen Klassert Signed-off-by: Ben Hutchings --- net/xfrm/xfrm_user.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -869,7 +869,8 @@ static int xfrm_dump_sa_done(struct netl struct sock *sk = cb->skb->sk; struct net *net = sock_net(sk); - xfrm_state_walk_done(walk, net); + if (cb->args[0]) + xfrm_state_walk_done(walk, net); return 0; } @@ -894,8 +895,6 @@ static int xfrm_dump_sa(struct sk_buff * u8 proto = 0; int err; - cb->args[0] = 1; - err = nlmsg_parse(cb->nlh, 0, attrs, XFRMA_MAX, xfrma_policy); if (err < 0) @@ -914,6 +913,7 @@ static int xfrm_dump_sa(struct sk_buff * proto = nla_get_u8(attrs[XFRMA_PROTO]); xfrm_state_walk_init(walk, proto, filter); + cb->args[0] = 1; } (void) xfrm_state_walk(net, walk, dump_one_state, &info);