From nobody Wed Sep 3 06:41:51 2025 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 4A3FCC38A2D for ; Mon, 24 Oct 2022 12:25:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233597AbiJXMZU (ORCPT ); Mon, 24 Oct 2022 08:25:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233543AbiJXMXp (ORCPT ); Mon, 24 Oct 2022 08:23:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F605275F3; Mon, 24 Oct 2022 04:59:54 -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 EDEB461257; Mon, 24 Oct 2022 11:59:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C0C1C433D6; Mon, 24 Oct 2022 11:59:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612793; bh=7JSOKnN3EJHVsIrkcfYIdDr89HElem67G5x8SxQh7dA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b2lvme8Pg1gThCv+SinYO8YoZlHJ3qKuDzbjJVJKGxqwLBoiaJS5v8ZOq284ugXqf m1/vpHPFMl4z5NNh3z13pn3mZgBlYR/1FTK3/aDn56kXmrcz/qGBo8nKii9Pco1ucQ iEH3qwgNHKSfjJ2NmpDujjZ64mjXvpR2YBGoHpJk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Hillf Danton , Tetsuo Handa , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 090/229] net: rds: dont hold sock lock when cancelling work from rds_tcp_reset_callbacks() Date: Mon, 24 Oct 2022 13:30:09 +0200 Message-Id: <20221024113001.961587129@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Tetsuo Handa [ Upstream commit a91b750fd6629354460282bbf5146c01b05c4859 ] syzbot is reporting lockdep warning at rds_tcp_reset_callbacks() [1], for commit ac3615e7f3cffe2a ("RDS: TCP: Reduce code duplication in rds_tcp_reset_callbacks()") added cancel_delayed_work_sync() into a section protected by lock_sock() without realizing that rds_send_xmit() might call lock_sock(). We don't need to protect cancel_delayed_work_sync() using lock_sock(), for even if rds_{send,recv}_worker() re-queued this work while __flush_work() from cancel_delayed_work_sync() was waiting for this work to complete, retried rds_{send,recv}_worker() is no-op due to the absence of RDS_CONN_UP bit. Link: https://syzkaller.appspot.com/bug?extid=3D78c55c7bc6f66e53dce2 [1] Reported-by: syzbot Co-developed-by: Hillf Danton Signed-off-by: Hillf Danton Signed-off-by: Tetsuo Handa Tested-by: syzbot Fixes: ac3615e7f3cffe2a ("RDS: TCP: Reduce code duplication in rds_tcp_rese= t_callbacks()") Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/rds/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/tcp.c b/net/rds/tcp.c index d4e6466d3989..645cbb17c13a 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -176,10 +176,10 @@ void rds_tcp_reset_callbacks(struct socket *sock, */ atomic_set(&cp->cp_state, RDS_CONN_RESETTING); wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags)); - lock_sock(osock->sk); /* reset receive side state for rds_tcp_data_recv() for osock */ cancel_delayed_work_sync(&cp->cp_send_w); cancel_delayed_work_sync(&cp->cp_recv_w); + lock_sock(osock->sk); if (tc->t_tinc) { rds_inc_put(&tc->t_tinc->ti_inc); tc->t_tinc =3D NULL; --=20 2.35.1