From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: [PATCH 3/4] xfrm: policy: check policy direction value Date: Mon, 21 Aug 2017 08:08:02 +0200 Message-ID: <1503295683-19153-4-git-send-email-steffen.klassert@secunet.com> References: <1503295683-19153-1-git-send-email-steffen.klassert@secunet.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , Steffen Klassert , To: David Miller Return-path: Received: from a.mx.secunet.com ([62.96.220.36]:35478 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077AbdHUGIL (ORCPT ); Mon, 21 Aug 2017 02:08:11 -0400 In-Reply-To: <1503295683-19153-1-git-send-email-steffen.klassert@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Vladis Dronov The 'dir' parameter in xfrm_migrate() is a user-controlled byte which is used as an array index. This can lead to an out-of-bound access, kernel lockup and DoS. Add a check for the 'dir' value. This fixes CVE-2017-11600. References: https://bugzilla.redhat.com/show_bug.cgi?id=1474928 Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)") Cc: # v2.6.21-rc1 Reported-by: "bo Zhang" Signed-off-by: Vladis Dronov Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index ff61d85..6f5a0dad 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3308,9 +3308,15 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, struct xfrm_state *x_new[XFRM_MAX_DEPTH]; struct xfrm_migrate *mp; + /* Stage 0 - sanity checks */ if ((err = xfrm_migrate_check(m, num_migrate)) < 0) goto out; + if (dir >= XFRM_POLICY_MAX) { + err = -EINVAL; + goto out; + } + /* Stage 1 - find policy */ if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) { err = -ENOENT; -- 2.7.4