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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 1F2CEC2D0F3 for ; Wed, 1 Apr 2020 16:38:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0FE8206F8 for ; Wed, 1 Apr 2020 16:37:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759079; bh=M1yKdC1PMPoCU3jcC9N0KAwktw1FvUgurSJb8673bKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a4GeoRihPj9W1erwGcAP1hmK16xG4bG2HSibzHnwgZNOhc+v1mXI9bqHKDjIhJz0Q QbaIJlUaao1ETmS1E8A2P1tOmACkQvql+4PDEUtdEYnHlmih4+cXsdC57QVs2uFovJ vM4HHqpyMun8yQhWgKf2DHNHc8OnNCKlOMI2VENs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389036AbgDAQh6 (ORCPT ); Wed, 1 Apr 2020 12:37:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:37242 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389024AbgDAQhw (ORCPT ); Wed, 1 Apr 2020 12:37:52 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 44CC1206F8; Wed, 1 Apr 2020 16:37:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759071; bh=M1yKdC1PMPoCU3jcC9N0KAwktw1FvUgurSJb8673bKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VE/X+JoR24h2jeNcfy3z20lipGtIZdeyANf1zbmdhS6sdelG+a1cgnECPRg8hz2Cn PB38UDNA63mjpW3FxIkMYkg56VvmYv4bszBBj5L8vPMrX6wS2ZGqILCfWtMYVuZtGL 4yX8jsEXHA7Bnjpay+sD8NjRaYIO/8dsd7mFmVdU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hangbin Liu , Xin Long , Steffen Klassert Subject: [PATCH 4.9 067/102] xfrm: add the missing verify_sec_ctx_len check in xfrm_add_acquire Date: Wed, 1 Apr 2020 18:18:10 +0200 Message-Id: <20200401161544.014427547@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161530.451355388@linuxfoundation.org> References: <20200401161530.451355388@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xin Long commit a1a7e3a36e01ca6e67014f8cf673cb8e47be5550 upstream. Without doing verify_sec_ctx_len() check in xfrm_add_acquire(), it may be out-of-bounds to access uctx->ctx_str with uctx->ctx_len, as noticed by syz: BUG: KASAN: slab-out-of-bounds in selinux_xfrm_alloc_user+0x237/0x430 Read of size 768 at addr ffff8880123be9b4 by task syz-executor.1/11650 Call Trace: dump_stack+0xe8/0x16e print_address_description.cold.3+0x9/0x23b kasan_report.cold.4+0x64/0x95 memcpy+0x1f/0x50 selinux_xfrm_alloc_user+0x237/0x430 security_xfrm_policy_alloc+0x5c/0xb0 xfrm_policy_construct+0x2b1/0x650 xfrm_add_acquire+0x21d/0xa10 xfrm_user_rcv_msg+0x431/0x6f0 netlink_rcv_skb+0x15a/0x410 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x50e/0x6a0 netlink_sendmsg+0x8ae/0xd40 sock_sendmsg+0x133/0x170 ___sys_sendmsg+0x834/0x9a0 __sys_sendmsg+0x100/0x1e0 do_syscall_64+0xe5/0x660 entry_SYSCALL_64_after_hwframe+0x6a/0xdf So fix it by adding the missing verify_sec_ctx_len check there. Fixes: 980ebd25794f ("[IPSEC]: Sync series - acquire insert") Reported-by: Hangbin Liu Signed-off-by: Xin Long Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/xfrm/xfrm_user.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2178,6 +2178,9 @@ static int xfrm_add_acquire(struct sk_bu err = verify_newpolicy_info(&ua->policy); if (err) goto free_state; + err = verify_sec_ctx_len(attrs); + if (err) + goto free_state; /* build an XP */ xp = xfrm_policy_construct(net, &ua->policy, attrs, &err);