From patchwork Wed Aug 26 12:02:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 264895 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=-10.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 B25D3C433E1 for ; Wed, 26 Aug 2020 12:03:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92F2D20838 for ; Wed, 26 Aug 2020 12:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598443386; bh=RmXL/1u0VAWNbKLafrCpKWutDzDTHZH6Cc5wbc73xbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cmPuqkGfNrWV/ihOGxYdRio+VXsKuehigGh2F9KJ7qJvklMkm8qre1mjApSZj2QqR GTRMSsCkafzHxYED3KybPyNoU0ufr3RUmSoTbmP2qEyfCGyaqWx7Idhj16LvLVDZTQ p1qxLNT6RPQoXXzfmWx21zLWJnWS1lbtMSkvRZJE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729497AbgHZMDD (ORCPT ); Wed, 26 Aug 2020 08:03:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:37486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729484AbgHZMC5 (ORCPT ); Wed, 26 Aug 2020 08:02:57 -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 4D73420786; Wed, 26 Aug 2020 12:02:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598443377; bh=RmXL/1u0VAWNbKLafrCpKWutDzDTHZH6Cc5wbc73xbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2mb+jiFtFoM8nZsakS4jNxo2a/D2iin9vayTfEOXlIWYi4Xk1g5f4+BG9H/ODY/3v x56+98IGMAvsUix4H3CapMt04DRwsKrPgYCirVqZ66k9AEpr+NF3KVvrrQfb4NKgaR vBrl9wRtd1M4Ky3rbGfRyejtpCwMwJ1yyQN1VQGI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Maloy , Ying Xue , Richard Alpe , Cong Wang , "David S. Miller" , syzbot+0e7181deafa7e0b79923@syzkaller.appspotmail.com Subject: [PATCH 5.7 09/15] tipc: fix uninit skb->data in tipc_nl_compat_dumpit() Date: Wed, 26 Aug 2020 14:02:37 +0200 Message-Id: <20200826114849.751629016@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200826114849.295321031@linuxfoundation.org> References: <20200826114849.295321031@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit 47733f9daf4fe4f7e0eb9e273f21ad3a19130487 ] __tipc_nl_compat_dumpit() has two callers, and it expects them to pass a valid nlmsghdr via arg->data. This header is artificial and crafted just for __tipc_nl_compat_dumpit(). tipc_nl_compat_publ_dump() does so by putting a genlmsghdr as well as some nested attribute, TIPC_NLA_SOCK. But the other caller tipc_nl_compat_dumpit() does not, this leaves arg->data uninitialized on this call path. Fix this by just adding a similar nlmsghdr without any payload in tipc_nl_compat_dumpit(). This bug exists since day 1, but the recent commit 6ea67769ff33 ("net: tipc: prepare attrs in __tipc_nl_compat_dumpit()") makes it easier to appear. Reported-and-tested-by: syzbot+0e7181deafa7e0b79923@syzkaller.appspotmail.com Fixes: d0796d1ef63d ("tipc: convert legacy nl bearer dump to nl compat") Cc: Jon Maloy Cc: Ying Xue Cc: Richard Alpe Signed-off-by: Cong Wang Acked-by: Ying Xue Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/netlink_compat.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -275,8 +275,9 @@ err_out: static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, struct tipc_nl_compat_msg *msg) { - int err; + struct nlmsghdr *nlh; struct sk_buff *arg; + int err; if (msg->req_type && (!msg->req_size || !TLV_CHECK_TYPE(msg->req, msg->req_type))) @@ -305,6 +306,15 @@ static int tipc_nl_compat_dumpit(struct return -ENOMEM; } + nlh = nlmsg_put(arg, 0, 0, tipc_genl_family.id, 0, NLM_F_MULTI); + if (!nlh) { + kfree_skb(arg); + kfree_skb(msg->rep); + msg->rep = NULL; + return -EMSGSIZE; + } + nlmsg_end(arg, nlh); + err = __tipc_nl_compat_dumpit(cmd, msg, arg); if (err) { kfree_skb(msg->rep);