From patchwork Wed Aug 4 07:03:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 492781 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=-16.8 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 45C1CC4338F for ; Wed, 4 Aug 2021 07:03:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B24960F56 for ; Wed, 4 Aug 2021 07:03:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235744AbhHDHDq (ORCPT ); Wed, 4 Aug 2021 03:03:46 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:41818 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235719AbhHDHDp (ORCPT ); Wed, 4 Aug 2021 03:03:45 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id AB062205F4; Wed, 4 Aug 2021 09:03:32 +0200 (CEST) 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 yZ9MpJwZZq5o; Wed, 4 Aug 2021 09:03:32 +0200 (CEST) Received: from mailout1.secunet.com (mailout1.secunet.com [62.96.220.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id E2B28205E3; Wed, 4 Aug 2021 09:03:31 +0200 (CEST) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) by mailout1.secunet.com (Postfix) with ESMTP id DC9C280004A; Wed, 4 Aug 2021 09:03:31 +0200 (CEST) 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 15.1.2176.2; Wed, 4 Aug 2021 09:03:31 +0200 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 15.1.2176.2; Wed, 4 Aug 2021 09:03:31 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 0539A31800D1; Wed, 4 Aug 2021 09:03:31 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 1/6] net: xfrm: fix memory leak in xfrm_user_rcv_msg Date: Wed, 4 Aug 2021 09:03:24 +0200 Message-ID: <20210804070329.1357123-2-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210804070329.1357123-1-steffen.klassert@secunet.com> References: <20210804070329.1357123-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) 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 From: Pavel Skripkin Syzbot reported memory leak in xfrm_user_rcv_msg(). The problem was is non-freed skb's frag_list. In skb_release_all() skb_release_data() will be called only in case of skb->head != NULL, but netlink_skb_destructor() sets head to NULL. So, allocated frag_list skb should be freed manualy, since consume_skb() won't take care of it Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Reported-and-tested-by: syzbot+fb347cf82c73a90efcca@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_user.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index b47d613409b7..7aff641c717d 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2811,6 +2811,16 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, err = link->doit(skb, nlh, attrs); + /* We need to free skb allocated in xfrm_alloc_compat() before + * returning from this function, because consume_skb() won't take + * care of frag_list since netlink destructor sets + * sbk->head to NULL. (see netlink_skb_destructor()) + */ + if (skb_has_frag_list(skb)) { + kfree_skb(skb_shinfo(skb)->frag_list); + skb_shinfo(skb)->frag_list = NULL; + } + err: kvfree(nlh64); return err;