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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37772C77B76 for ; Tue, 18 Apr 2023 12:53:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232195AbjDRMxS (ORCPT ); Tue, 18 Apr 2023 08:53:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232128AbjDRMxP (ORCPT ); Tue, 18 Apr 2023 08:53:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01C8F13C1F for ; Tue, 18 Apr 2023 05:52:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B92A963437 for ; Tue, 18 Apr 2023 12:52:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDEE3C433D2; Tue, 18 Apr 2023 12:52:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681822373; bh=f2fTbvyjmUZ+F597QbBJuqwuDksjeIew8pO/V1G1zDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p5T7btfr3El4Tg+s1Ne29B2P5u/V4VBKavgwrtQ4DKx0Xk86xUfd0MO+Ha+DSIxOP sE4SWCjq1hL0Kcc201K7YZYBhsOtqOE/wwA0ZimvhPYG4GOQCRM3nWzxiikwAYRvKq OZYb/enC+4s+/QVs62MaJQfxWgoWFc1/bsAB9afU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Paasch , Paolo Abeni , Matthieu Baerts , Jakub Kicinski Subject: [PATCH 6.2 125/139] mptcp: stricter state check in mptcp_worker Date: Tue, 18 Apr 2023 14:23:10 +0200 Message-Id: <20230418120318.550235353@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120313.725598495@linuxfoundation.org> References: <20230418120313.725598495@linuxfoundation.org> User-Agent: quilt/0.67 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: Paolo Abeni commit d6a0443733434408f2cbd4c53fea6910599bab9e upstream. As reported by Christoph, the mptcp protocol can run the worker when the relevant msk socket is in an unexpected state: connect() // incoming reset + fastclose // the mptcp worker is scheduled mptcp_disconnect() // msk is now CLOSED listen() mptcp_worker() Leading to the following splat: divide error: 0000 [#1] PREEMPT SMP CPU: 1 PID: 21 Comm: kworker/1:0 Not tainted 6.3.0-rc1-gde5e8fd0123c #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Workqueue: events mptcp_worker RIP: 0010:__tcp_select_window+0x22c/0x4b0 net/ipv4/tcp_output.c:3018 RSP: 0018:ffffc900000b3c98 EFLAGS: 00010293 RAX: 000000000000ffd7 RBX: 000000000000ffd7 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8214ce97 RDI: 0000000000000004 RBP: 000000000000ffd7 R08: 0000000000000004 R09: 0000000000010000 R10: 000000000000ffd7 R11: ffff888005afa148 R12: 000000000000ffd7 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000405270 CR3: 000000003011e006 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_select_window net/ipv4/tcp_output.c:262 [inline] __tcp_transmit_skb+0x356/0x1280 net/ipv4/tcp_output.c:1345 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline] tcp_send_active_reset+0x13e/0x320 net/ipv4/tcp_output.c:3459 mptcp_check_fastclose net/mptcp/protocol.c:2530 [inline] mptcp_worker+0x6c7/0x800 net/mptcp/protocol.c:2705 process_one_work+0x3bd/0x950 kernel/workqueue.c:2390 worker_thread+0x5b/0x610 kernel/workqueue.c:2537 kthread+0x138/0x170 kernel/kthread.c:376 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 This change addresses the issue explicitly checking for bad states before running the mptcp worker. Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch Link: https://github.com/multipath-tcp/mptcp_net-next/issues/374 Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts Tested-by: Christoph Paasch Signed-off-by: Matthieu Baerts Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2627,7 +2627,7 @@ static void mptcp_worker(struct work_str lock_sock(sk); state = sk->sk_state; - if (unlikely(state == TCP_CLOSE)) + if (unlikely((1 << state) & (TCPF_CLOSE | TCPF_LISTEN))) goto unlock; mptcp_check_data_fin_ack(sk);