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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 42AC8C4338F for ; Tue, 10 Aug 2021 17:43:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2574E6135D for ; Tue, 10 Aug 2021 17:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233181AbhHJRoC (ORCPT ); Tue, 10 Aug 2021 13:44:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:34382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234253AbhHJRkI (ORCPT ); Tue, 10 Aug 2021 13:40:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 372476109F; Tue, 10 Aug 2021 17:37:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628617076; bh=R//KGMnHgn3imwAr23wCSUTcCP7r7swND//LrSgLaF8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FFN9qYgIdnIxIlEi/SAoSi9Zwbqu0Ep1w8jG6aCJTAO9k7X0vSC1fbx4C1rLkZ4Sj CSpCnzZPVSKaNJKy7vyOkLW0wP+HLIpz3orYAHS3eRsHYF1j+akmPL5iLXdkAgOuWj AVVYcchmKlVoynt6l5bSO/g2ZMpecgG7p41Fb0zE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Skripkin , Steffen Klassert , Sasha Levin , syzbot+fb347cf82c73a90efcca@syzkaller.appspotmail.com Subject: [PATCH 5.10 004/135] net: xfrm: fix memory leak in xfrm_user_rcv_msg Date: Tue, 10 Aug 2021 19:28:58 +0200 Message-Id: <20210810172955.821047403@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810172955.660225700@linuxfoundation.org> References: <20210810172955.660225700@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit 7c1a80e80cde008f271bae630d28cf684351e807 ] 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 Signed-off-by: Sasha Levin --- 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 45f86a97eaf2..6f97665b632e 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2751,6 +2751,16 @@ 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; -- 2.30.2