From patchwork Wed Jan 2 18:14:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrei Vagin X-Patchwork-Id: 10746635 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0A58D6C5 for ; Wed, 2 Jan 2019 18:14:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF3BC283AF for ; Wed, 2 Jan 2019 18:14:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E31E6283EE; Wed, 2 Jan 2019 18:14:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B48D283AF for ; Wed, 2 Jan 2019 18:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727762AbfABSOS (ORCPT ); Wed, 2 Jan 2019 13:14:18 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:32814 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726609AbfABSOS (ORCPT ); Wed, 2 Jan 2019 13:14:18 -0500 Received: by mail-pf1-f194.google.com with SMTP id c123so15516929pfb.0; Wed, 02 Jan 2019 10:14:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=UR/RAZjykfJ5Y3FNJ1fwGQlIyrymlchuoc/Gy1KCleQ=; b=gYZwSpMsAKYpA10MQS+kxzHb3Qv7s3nsq3vtivEQK05G86On3biflMg39tqUnfAy2x Rdp4SeHTI9h5nXBCd3bW+lo6IEeR/Fg9PJS+gWxt7tLkLPZ4UZDLq/kqyRpOBdW62tZz BoOzTwBbwrDxFjyWdActJTUD9yyQuE8RkzZpYiYXzsGOHtC0y45x/wLkuPmM/M8eEAKK F3qwPIrsmfDYI8K1UBUopS1Snm4JFxRcoXRHen75TNRIUAeqPGD7ApH6yjeKAyzROgYD hs10jlwau/KIUWsitnF9ch3N4BZVU6xhmqqEnLtA9Nk/2AI605xE0yq3ATDh/8CgOhV7 D3Cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=UR/RAZjykfJ5Y3FNJ1fwGQlIyrymlchuoc/Gy1KCleQ=; b=Yb+JReJ5gkWwCffsav8McAtAHLg3F2jtpAkZ0rTLlTp86k81wCIckMwY6HaQE8bzkQ 4RYdKIPuDjjANBHNBaeSmT1WIrWBEQxsomDM5hgbkadTyH6oat1KJqjOMRB7jEU717ij CWI7vccW2VCnxq+wUS0yTFF0KVEvdzJMB37Qad3tW1Btyt3yyIwXGbMEJwg4S+OgFIHQ bidO25Xe67FFlxahxdPZ5g0p1sHUh4O44CSa+WRqvXJMW4Q/dL6yd5sEZTuZxruU0oJs wFZSQhooLqLvDkB+iCR4eB5siMgkB6kvy9M54D1vcc+R1VoG77eJ7FGUcnPUOdokysdx u1HQ== X-Gm-Message-State: AJcUukcItkABALiRY62u4tl+Gjd4oUy7kcGUNxOK6K8PLuHITy6GeR2A ZiT3cmnUVsYI3aeTGqixWXA= X-Google-Smtp-Source: ALg8bN6HZZn93LNMzkzm6yj3q+fn3Mm5IjMa8Oe30GLOpsGlSGkP9kmMHqKTUVusL2J2Y7o1eJEwMA== X-Received: by 2002:a63:78cd:: with SMTP id t196mr14401589pgc.62.1546452856641; Wed, 02 Jan 2019 10:14:16 -0800 (PST) Received: from localhost.localdomain ([2620:0:1008:fd00:78b4:3a07:980a:287b]) by smtp.gmail.com with ESMTPSA id o7sm71653727pfb.34.2019.01.02.10.14.15 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 02 Jan 2019 10:14:16 -0800 (PST) From: Andrei Vagin To: Alexander Viro , David Howells Cc: linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, Andrei Vagin , Li Zefan Subject: [PATCH vfs/for-next v3] cgroup: fix top cgroup refcnt leak Date: Wed, 2 Jan 2019 10:14:13 -0800 Message-Id: <20190102181413.7003-1-avagin@gmail.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190102022804.GH2217@ZenIV.linux.org.uk> References: <20190102022804.GH2217@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It looks like the c6b3d5bcd67c ("cgroup: fix top cgroup refcnt leak") commit was reverted by mistake. $ mkdir /tmp/cgroup $ mkdir /tmp/cgroup2 $ mount -t cgroup -o none,name=test test /tmp/cgroup $ mount -t cgroup -o none,name=test test /tmp/cgroup2 $ umount /tmp/cgroup $ umount /tmp/cgroup2 $ cat /proc/self/cgroup | grep test 12:name=test:/ You can see the test cgroup was not freed. Cc: Li Zefan Fixes: aea3f2676c83 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context") Signed-off-by: Andrei Vagin --- v2: clean up code and add the vfs/for-next tag v3: fix a reference leak when kernfs_node_dentry fails kernel/cgroup/cgroup.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index fb0717696895..b43479d1f9a3 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2019,7 +2019,7 @@ int cgroup_do_get_tree(struct fs_context *fc) ret = kernfs_get_tree(fc); if (ret < 0) - goto out_cgrp; + return ret; /* * In non-init cgroup namespace, instead of root cgroup's dentry, @@ -2038,19 +2038,22 @@ int cgroup_do_get_tree(struct fs_context *fc) mutex_unlock(&cgroup_mutex); nsdentry = kernfs_node_dentry(cgrp->kn, fc->root->d_sb); - if (IS_ERR(nsdentry)) - return PTR_ERR(nsdentry); + if (IS_ERR(nsdentry)) { + ret = PTR_ERR(nsdentry); + goto out_cgrp; + } dput(fc->root); fc->root = nsdentry; } ret = 0; - if (ctx->kfc.new_sb_created) - goto out_cgrp; - apply_cgroup_root_flags(ctx->flags); - return 0; + if (!ctx->kfc.new_sb_created) + apply_cgroup_root_flags(ctx->flags); out_cgrp: + if (!ctx->kfc.new_sb_created) + cgroup_put(&ctx->root->cgrp); + return ret; }