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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 83966C3A5A6 for ; Thu, 19 Sep 2019 22:29:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5509021920 for ; Thu, 19 Sep 2019 22:29:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568932162; bh=NFX9SeBlJI3kFLNjhMymOFTXGp/Qy3T/wRkNDUfJJrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Phkv68F5SP4eiqdWsWyNf69zgv5ce7+JAAGJBcFWWtIV7pgxZW1MPH26xXOhmWDbY ALPhObMSII6VKZBg2ZJ44hGHxR+gynBHYUXlTpez89vXE1NNtdcca8K6sVhkmrBHGC eAw7WLhbZHtEmLKHETHCDMbi1wALaNnpiPGnZ9X8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392209AbfISW3V (ORCPT ); Thu, 19 Sep 2019 18:29:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:59098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406532AbfISWRt (ORCPT ); Thu, 19 Sep 2019 18:17:49 -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 221C9217D6; Thu, 19 Sep 2019 22:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568931468; bh=NFX9SeBlJI3kFLNjhMymOFTXGp/Qy3T/wRkNDUfJJrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CT56TTNE9XphFh0S2M23TgTUr6QgQBLf8BzBx+YdcJF3vc0Gwpayc6Xb4nIpdKh6a sDOUpMVU0Gs/IgDQfC09vZx3Ej/LIhfBuHE6lUXQ1YlmpRVSAjE6HrUNuLS3T406Dc 7EM2LLOghmuAEpcl9NEgRsDcgJGnfqEJw+c4fIec= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Jason Baron , Vladimir Rutsky , Soheil Hassas Yeganeh , Neal Cardwell , Christoph Paasch Subject: [PATCH 4.14 57/59] tcp: Reset send_head when removing skb from write-queue Date: Fri, 20 Sep 2019 00:04:12 +0200 Message-Id: <20190919214808.366745641@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214755.852282682@linuxfoundation.org> References: <20190919214755.852282682@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: Christoph Paasch syzkaller is not happy since commit fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases"): CPU: 1 PID: 13814 Comm: syz-executor.4 Not tainted 4.14.143 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011 task: ffff888040105c00 task.stack: ffff8880649c0000 RIP: 0010:tcp_sendmsg_locked+0x6b4/0x4390 net/ipv4/tcp.c:1350 RSP: 0018:ffff8880649cf718 EFLAGS: 00010206 RAX: 0000000000000014 RBX: 000000000000001e RCX: ffffc90000717000 RDX: 0000000000000077 RSI: ffffffff82e760f7 RDI: 00000000000000a0 RBP: ffff8880649cfaa8 R08: 1ffff1100c939e7a R09: ffff8880401063c8 R10: 0000000000000003 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff888043d74750 R14: ffff888043d74500 R15: 000000000000001e FS: 00007f0afcb6d700(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ca22000 CR3: 0000000040496004 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_sendmsg+0x2a/0x40 net/ipv4/tcp.c:1533 inet_sendmsg+0x173/0x4e0 net/ipv4/af_inet.c:784 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc3/0x100 net/socket.c:656 SYSC_sendto+0x35d/0x5e0 net/socket.c:1766 do_syscall_64+0x241/0x680 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The problem is that we are removing an skb from the write-queue that could have been referenced by the sk_send_head. Thus, we need to check for the send_head's sanity after removing it. This patch needs to be backported only to 4.14 and older (among those that applied the backport of fdfc5c8594c2). Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases") Cc: Eric Dumazet Cc: Jason Baron Cc: Vladimir Rutsky Cc: Soheil Hassas Yeganeh Cc: Neal Cardwell Signed-off-by: Christoph Paasch Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -924,8 +924,7 @@ static void tcp_remove_empty_skb(struct { if (skb && !skb->len) { tcp_unlink_write_queue(skb, sk); - if (tcp_write_queue_empty(sk)) - tcp_chrono_stop(sk, TCP_CHRONO_BUSY); + tcp_check_send_head(sk, skb); sk_wmem_free_skb(sk, skb); } }