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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 68A79C433E0 for ; Tue, 7 Jul 2020 15:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E34E206E2 for ; Tue, 7 Jul 2020 15:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594135901; bh=G6FFFYTDNCTwUdbAjyx5dcVHoIVHA2U+0o5krRR/nes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=B3PB6Fu+EizN30K8JBODDMX6i3TOk3YmmpReftzarb15sqS4Iia3pvugBQzI8jWMs URX4g7aa/SBFu6/4FtS2NR0egQ/UEVa8KFsiT0B8FfFYEq0Aym4GX04xl5NrkWSgJN edhiTNVpEyQrOryiEWosorAJHug/KjgDryOyh7UY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729921AbgGGPW4 (ORCPT ); Tue, 7 Jul 2020 11:22:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:35658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728356AbgGGPWw (ORCPT ); Tue, 7 Jul 2020 11:22:52 -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 031B72065D; Tue, 7 Jul 2020 15:22:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594135372; bh=G6FFFYTDNCTwUdbAjyx5dcVHoIVHA2U+0o5krRR/nes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S/J49EMu60KRVwev+LG/uQ6HhVazM3Uxk8n8rescgJ6Kk8LAiPLHUm75n0q1cAuM7 7bLFPkOwtTK2dxrwp3jpDYdqzry3sDAnQ/aqp1sRLdt9AsyehWX2JV/wOqF4iL8QMg hQfWy4A10UdNTrQnnPSR9JRprpqqkOMDnWmul+OQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+8eac6d030e7807c21d32@syzkaller.appspotmail.com, YueHaibing , "David S. Miller" , Sasha Levin Subject: [PATCH 5.7 015/112] tipc: Fix NULL pointer dereference in __tipc_sendstream() Date: Tue, 7 Jul 2020 17:16:20 +0200 Message-Id: <20200707145801.721076283@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707145800.925304888@linuxfoundation.org> References: <20200707145800.925304888@linuxfoundation.org> User-Agent: quilt/0.66 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 From: YueHaibing [ Upstream commit 4c21daae3dbc9f8536cc18e6e53627821fa2c90c ] tipc_sendstream() may send zero length packet, then tipc_msg_append() do not alloc skb, skb_peek_tail() will get NULL, msg_set_ack_required will trigger NULL pointer dereference. Reported-by: syzbot+8eac6d030e7807c21d32@syzkaller.appspotmail.com Fixes: 0a3e060f340d ("tipc: add test for Nagle algorithm effectiveness") Signed-off-by: YueHaibing Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tipc/socket.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 62fc871a8d673..f02f2abf6e3c0 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1589,8 +1589,12 @@ static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dlen) tsk->pkt_cnt += skb_queue_len(txq); } else { skb = skb_peek_tail(txq); - msg_set_ack_required(buf_msg(skb)); - tsk->expect_ack = true; + if (skb) { + msg_set_ack_required(buf_msg(skb)); + tsk->expect_ack = true; + } else { + tsk->expect_ack = false; + } tsk->msg_acc = 0; tsk->pkt_cnt = 0; } -- 2.25.1