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,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 C80ADFA372C for ; Fri, 8 Nov 2019 19:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1C5E21D7B for ; Fri, 8 Nov 2019 19:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573240277; bh=09BxqHp169q6fr0ZCElDEycFydF5NK0HyBEQ4yC+1cA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1+3TS03l6s2ydXxXlVZkyv6Rgtqr8/a0+xJayECD2qq2fcPldqyKPn5Ll2Y6E1T/X t/Y7CT4MCYtOJOYCyAbliwLDCP9rd335jiKNxC2Cg3/dQF2PeP1jWoXfsafRTL+v/Y r0jK7PCdY2JcVYuz5H53entqAoeGP5ssKuqT492k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389306AbfKHTLQ (ORCPT ); Fri, 8 Nov 2019 14:11:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:43626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391997AbfKHTLO (ORCPT ); Fri, 8 Nov 2019 14:11:14 -0500 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 2925A206A3; Fri, 8 Nov 2019 19:11:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573240273; bh=09BxqHp169q6fr0ZCElDEycFydF5NK0HyBEQ4yC+1cA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ErSpFERoDImty+s2xpanS1JWjMEQjc3bgd5KWoeU2jSb9MF+T5QNQdH6Lm4S1rN76 BYeQABMDhm+Jx7XGrrDGvwk+uCmnf32PG921T9AcFukphBwqPt+xcOI5xb17LK7Sa1 uAOIitk31w9upTZokremqawnk9sa+hzjS53sK0K8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+4c063e6dea39e4b79f29@syzkaller.appspotmail.com, Karsten Graul , Ursula Braun , "David S. Miller" Subject: [PATCH 5.3 114/140] net/smc: fix refcounting for non-blocking connect() Date: Fri, 8 Nov 2019 19:50:42 +0100 Message-Id: <20191108174912.010960142@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191108174900.189064908@linuxfoundation.org> References: <20191108174900.189064908@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ursula Braun [ Upstream commit 301428ea3708188dc4a243e6e6b46c03b46a0fbc ] If a nonblocking socket is immediately closed after connect(), the connect worker may not have started. This results in a refcount problem, since sock_hold() is called from the connect worker. This patch moves the sock_hold in front of the connect worker scheduling. Reported-by: syzbot+4c063e6dea39e4b79f29@syzkaller.appspotmail.com Fixes: 50717a37db03 ("net/smc: nonblocking connect rework") Reviewed-by: Karsten Graul Signed-off-by: Ursula Braun Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/smc/af_smc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -707,8 +707,6 @@ static int __smc_connect(struct smc_sock int smc_type; int rc = 0; - sock_hold(&smc->sk); /* sock put in passive closing */ - if (smc->use_fallback) return smc_connect_fallback(smc, smc->fallback_rsn); @@ -853,6 +851,8 @@ static int smc_connect(struct socket *so rc = kernel_connect(smc->clcsock, addr, alen, flags); if (rc && rc != -EINPROGRESS) goto out; + + sock_hold(&smc->sk); /* sock put in passive closing */ if (flags & O_NONBLOCK) { if (schedule_work(&smc->connect_work)) smc->connect_nonblock = 1;