From patchwork Mon Dec 7 09:39:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 11955221 X-Patchwork-Delegate: kuba@kernel.org 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 528FDC19437 for ; Mon, 7 Dec 2020 09:56:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C8382310B for ; Mon, 7 Dec 2020 09:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726788AbgLGJ4Q (ORCPT ); Mon, 7 Dec 2020 04:56:16 -0500 Received: from a.mx.secunet.com ([62.96.220.36]:49432 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726044AbgLGJ4M (ORCPT ); Mon, 7 Dec 2020 04:56:12 -0500 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 34C2E204EF; Mon, 7 Dec 2020 10:55:31 +0100 (CET) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6vtN618LYGm1; Mon, 7 Dec 2020 10:55:27 +0100 (CET) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 399C120491; Mon, 7 Dec 2020 10:55:27 +0100 (CET) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 7 Dec 2020 10:55:27 +0100 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2044.4; Mon, 7 Dec 2020 10:55:26 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 9B6933182E6C; Mon, 7 Dec 2020 10:39:43 +0100 (CET) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 2/4] xfrm/compat: memset(0) 64-bit padding at right place Date: Mon, 7 Dec 2020 10:39:35 +0100 Message-ID: <20201207093937.2874932-3-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201207093937.2874932-1-steffen.klassert@secunet.com> References: <20201207093937.2874932-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-01.secunet.de (10.53.40.201) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Dmitry Safonov 32-bit messages translated by xfrm_compat can have attributes attached. For all, but XFRMA_SA, XFRMA_POLICY the size of payload is the same in 32-bit UABI and 64-bit UABI. For XFRMA_SA (struct xfrm_usersa_info) and XFRMA_POLICY (struct xfrm_userpolicy_info) it's only tail-padding that is present in 64-bit payload, but not in 32-bit. The proper size for destination nlattr is already calculated by xfrm_user_rcv_calculate_len64() and allocated with kvmalloc(). xfrm_attr_cpy32() copies 32-bit copy_len into 64-bit attribute translated payload, zero-filling possible padding for SA/POLICY. Due to a typo, *pos already has 64-bit payload size, in a result next memset(0) is called on the memory after the translated attribute, not on the tail-padding of it. Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Reported-by: syzbot+c43831072e7df506a646@syzkaller.appspotmail.com Signed-off-by: Dmitry Safonov Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_compat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index 17edbf935e35..556e9f33b815 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -388,7 +388,7 @@ static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src, memcpy(nla, src, nla_attr_size(copy_len)); nla->nla_len = nla_attr_size(payload); - *pos += nla_attr_size(payload); + *pos += nla_attr_size(copy_len); nlmsg->nlmsg_len += nla->nla_len; memset(dst + *pos, 0, payload - copy_len);