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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 C8C6AC2F3A0 for ; Mon, 21 Jan 2019 14:17:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 991C520861 for ; Mon, 21 Jan 2019 14:17:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548080256; bh=r1FLOFQhRI/aygtqGHDUNq3zvQXzf5uKQwwA8LDAFrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hEb4wbHZnPaPX3X6WOfM4srQXejRwjtDCw0Ia0QXXD/zFx4Ptj63YvAWRFhrPybSi KfQC5xZQQfZGOAqQ4BiMFb6EsSrzBLt4p8ATTXKQM8T+eE3ZQjAK4jQXPfKowGwb5M qhccHCAUVuiKIvM0Zdx66ufl20Vvkb9CI0vjtMAg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729573AbfAUNuV (ORCPT ); Mon, 21 Jan 2019 08:50:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:32810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730502AbfAUNuR (ORCPT ); Mon, 21 Jan 2019 08:50:17 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 6A3592063F; Mon, 21 Jan 2019 13:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548078616; bh=r1FLOFQhRI/aygtqGHDUNq3zvQXzf5uKQwwA8LDAFrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z3GtTN9O1nvkFjGRK50RvH//9fOt0xgQb7+nEb6knURN4aiFMk082fkQ9wRuOU/Jm jwFYnN4Vh5ynM1+SDOwr7MAl2kxKTnBu3kvW9lAEqShHDQxXBneO4XhWylSUWm7XoQ II/v56P4mKHo4ZflwpvafC3zjX6MuBoGPPj+/aA8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+8951a3065ee7fd6d6e23@syzkaller.appspotmail.com, syzbot+75e6e042c5bbf691fc82@syzkaller.appspotmail.com, Ying Xue , "David S. Miller" Subject: [PATCH 4.20 087/111] tipc: fix uninit-value in in tipc_conn_rcv_sub Date: Mon, 21 Jan 2019 14:43:21 +0100 Message-Id: <20190121122505.604781574@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190121122455.819406896@linuxfoundation.org> References: <20190121122455.819406896@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ying Xue commit a88289f4ddee4165d5f796bd99e09eec3133c16b upstream. syzbot reported: BUG: KMSAN: uninit-value in tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373 CPU: 0 PID: 66 Comm: kworker/u4:4 Not tainted 4.17.0-rc3+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_rcv tipc_conn_recv_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373 tipc_conn_rcv_from_sock net/tipc/topsrv.c:409 [inline] tipc_conn_recv_work+0x3cd/0x560 net/tipc/topsrv.c:424 process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145 worker_thread+0x113c/0x24f0 kernel/workqueue.c:2279 kthread+0x539/0x720 kernel/kthread.c:239 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:412 Local variable description: ----s.i@tipc_conn_recv_work Variable was created at: tipc_conn_recv_work+0x65/0x560 net/tipc/topsrv.c:419 process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145 In tipc_conn_rcv_from_sock(), it always supposes the length of message received from sock_recvmsg() is not smaller than the size of struct tipc_subscr. However, this assumption is false. Especially when the length of received message is shorter than struct tipc_subscr size, we will end up touching uninitialized fields in tipc_conn_rcv_sub(). Reported-by: syzbot+8951a3065ee7fd6d6e23@syzkaller.appspotmail.com Reported-by: syzbot+75e6e042c5bbf691fc82@syzkaller.appspotmail.com Signed-off-by: Ying Xue Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/topsrv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/tipc/topsrv.c +++ b/net/tipc/topsrv.c @@ -398,7 +398,7 @@ static int tipc_conn_rcv_from_sock(struc ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT); if (ret == -EWOULDBLOCK) return -EWOULDBLOCK; - if (ret > 0) { + if (ret == sizeof(s)) { read_lock_bh(&sk->sk_callback_lock); ret = tipc_conn_rcv_sub(srv, con, &s); read_unlock_bh(&sk->sk_callback_lock);