From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B512C43381 for ; Sat, 23 Feb 2019 21:13:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B9AD20651 for ; Sat, 23 Feb 2019 21:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956417; bh=8Cf9qlYpiaoprVaeSDYfKh5rueSja3jyHU/sDMHXMt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1xyPTe6lae7LxB68BBOBGfxTAbVXIpDQ2eOFFr6JC4THFvqdfSo8tf+FboRd7lZWO ZjmoGD16s/cVqpZF6EstCXB2vqDxckv9juAyu8kcaIHhIs0k9U6GFI4hVSD5PzO5PU Keh4dn/fAC71G/r0HJwuJyPZP1khjP8HiqCVVK5c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730048AbfBWVNc (ORCPT ); Sat, 23 Feb 2019 16:13:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:48230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728377AbfBWVLi (ORCPT ); Sat, 23 Feb 2019 16:11:38 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 65BC420861; Sat, 23 Feb 2019 21:11:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956298; bh=8Cf9qlYpiaoprVaeSDYfKh5rueSja3jyHU/sDMHXMt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TrM9U5WFm4jeECCb+XHXh4pvK7RnMMrQnf+ky8OzOtMbBwajXfeE0mmdFd+KVdRND wuAHyoYMTUF12a/uYFGu+vEfVFIAJsW97C9bwsgzAwHAsWqzcmmJkt5leOe5xIDQs5 em4I2WH8HYAvl8qJIjtztKviEy0gQPy0iyTdJe5s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Florian Westphal , Steffen Klassert , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 3.18 02/18] xfrm: refine validation of template and selector families Date: Sat, 23 Feb 2019 16:11:19 -0500 Message-Id: <20190223211135.203082-2-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190223211135.203082-1-sashal@kernel.org> References: <20190223211135.203082-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal [ Upstream commit 35e6103861a3a970de6c84688c6e7a1f65b164ca ] The check assumes that in transport mode, the first templates family must match the address family of the policy selector. Syzkaller managed to build a template using MODE_ROUTEOPTIMIZATION, with ipv4-in-ipv6 chain, leading to following splat: BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x1db/0x1854 Read of size 4 at addr ffff888063e57aa0 by task a.out/2050 xfrm_state_find+0x1db/0x1854 xfrm_tmpl_resolve+0x100/0x1d0 xfrm_resolve_and_create_bundle+0x108/0x1000 [..] Problem is that addresses point into flowi4 struct, but xfrm_state_find treats them as being ipv6 because it uses templ->encap_family is used (AF_INET6 in case of reproducer) rather than family (AF_INET). This patch inverts the logic: Enforce 'template family must match selector' EXCEPT for tunnel and BEET mode. In BEET and Tunnel mode, xfrm_tmpl_resolve_one will have remote/local address pointers changed to point at the addresses found in the template, rather than the flowi ones, so no oob read will occur. Reported-by: 3ntr0py1337@gmail.com Reported-by: Daniel Borkmann Signed-off-by: Florian Westphal Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_user.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 017b1c91d58ea..05b72d45dda05 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1377,10 +1377,15 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family) if (!ut[i].family) ut[i].family = family; - if ((ut[i].mode == XFRM_MODE_TRANSPORT) && - (ut[i].family != prev_family)) - return -EINVAL; - + switch (ut[i].mode) { + case XFRM_MODE_TUNNEL: + case XFRM_MODE_BEET: + break; + default: + if (ut[i].family != prev_family) + return -EINVAL; + break; + } if (ut[i].mode >= XFRM_MODE_MAX) return -EINVAL; -- 2.19.1