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=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 12DBFC19F41 for ; Mon, 26 Jul 2021 15:57:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F25B060F70 for ; Mon, 26 Jul 2021 15:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235965AbhGZPQw (ORCPT ); Mon, 26 Jul 2021 11:16:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:52932 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236626AbhGZPLv (ORCPT ); Mon, 26 Jul 2021 11:11:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AAB5660F92; Mon, 26 Jul 2021 15:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627314740; bh=+KBYrjKByNzhavMEVdFMXXuczM+Zb1GaVB6YfG7W/NQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KPkCTBiJ+Q0QjDWL+wGmvuQ1vQbnO/Imre1VPOHGJsuD1ao9LqJQtn44ZGnQa9lA+ UaTnZPROanRLdtrykIiuEYrIOxMKxAYcBZlkBVPA6lvgdJOt/LKci6joh09kqbOMmP J8GQln7Vq2uNlfJkADmIe2G/NNMQ6D9+AGmJUYRU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+09a5d591c1f98cf5efcb@syzkaller.appspotmail.com, Ziyang Xuan , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 075/120] net: fix uninit-value in caif_seqpkt_sendmsg Date: Mon, 26 Jul 2021 17:38:47 +0200 Message-Id: <20210726153834.789490925@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153832.339431936@linuxfoundation.org> References: <20210726153832.339431936@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: stable@vger.kernel.org From: Ziyang Xuan [ Upstream commit 991e634360f2622a683b48dfe44fe6d9cb765a09 ] When nr_segs equal to zero in iovec_from_user, the object msg->msg_iter.iov is uninit stack memory in caif_seqpkt_sendmsg which is defined in ___sys_sendmsg. So we cann't just judge msg->msg_iter.iov->base directlly. We can use nr_segs to judge msg in caif_seqpkt_sendmsg whether has data buffers. ===================================================== BUG: KMSAN: uninit-value in caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmmsg+0x808/0xc90 net/socket.c:2480 __compat_sys_sendmmsg net/compat.c:656 [inline] Reported-by: syzbot+09a5d591c1f98cf5efcb@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=1ace85e8fc9b0d5a45c08c2656c3e91762daa9b8 Fixes: bece7b2398d0 ("caif: Rewritten socket implementation") Signed-off-by: Ziyang Xuan Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/caif/caif_socket.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 4b31f0aaa96d..348b8cb0bc24 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -539,7 +539,8 @@ static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg, goto err; ret = -EINVAL; - if (unlikely(msg->msg_iter.iov->iov_base == NULL)) + if (unlikely(msg->msg_iter.nr_segs == 0) || + unlikely(msg->msg_iter.iov->iov_base == NULL)) goto err; noblock = msg->msg_flags & MSG_DONTWAIT; -- 2.30.2