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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D1E60C433E1 for ; Thu, 14 May 2020 18:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E45420767 for ; Thu, 14 May 2020 18:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482487; bh=UOJZ0yWknRPQ/UU9wETdMl2+JeJ1OHSK7xBKN67d78Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Vqu+jz1Vq+cD1sxWXyvQcXQkwKJ/sEjnlHg8CP91W05tOVq3lxvnSMXVxDg306BVv ZaE+fZJkSUEdblkhcizRVosBoOhQhztI2s95mTBmLfRCEXMdQ2GupPmOqUGzk6deqX StI+R6X1AKnRAqRNou9FJJ6hVPLvx8wqsZT9Oayw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729199AbgENSyq (ORCPT ); Thu, 14 May 2020 14:54:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:54436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729053AbgENSy0 (ORCPT ); Thu, 14 May 2020 14:54:26 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F3A2D2076A; Thu, 14 May 2020 18:54:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482465; bh=UOJZ0yWknRPQ/UU9wETdMl2+JeJ1OHSK7xBKN67d78Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=00w6VsZAobPz84i9MMMxCWPepMK2iQVInCaOJjWlMoGZIVQc/bFbQTfOB5C6tEthu G+WjjDLLgaEijx7tM3hgTFqe2o8jlSYJ3NpXkzwnHddgGVgMzVcq24FkqiQebj+8pX 9TzuQ9tfTuWS2IXNZn5HOx1B79kCwT7gTCvUThlY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiyu Yang , Xin Tan , Christoph Hellwig , Sasha Levin Subject: [PATCH AUTOSEL 4.19 09/31] configfs: fix config_item refcnt leak in configfs_rmdir() Date: Thu, 14 May 2020 14:53:51 -0400 Message-Id: <20200514185413.20755-9-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200514185413.20755-1-sashal@kernel.org> References: <20200514185413.20755-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiyu Yang [ Upstream commit 8aebfffacfa379ba400da573a5bf9e49634e38cb ] configfs_rmdir() invokes configfs_get_config_item(), which returns a reference of the specified config_item object to "parent_item" with increased refcnt. When configfs_rmdir() returns, local variable "parent_item" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of configfs_rmdir(). When down_write_killable() fails, the function forgets to decrease the refcnt increased by configfs_get_config_item(), causing a refcnt leak. Fix this issue by calling config_item_put() when down_write_killable() fails. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- fs/configfs/dir.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 2cc6b1c49d348..f9628fc20fec0 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1537,6 +1537,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) spin_lock(&configfs_dirent_lock); configfs_detach_rollback(dentry); spin_unlock(&configfs_dirent_lock); + config_item_put(parent_item); return -EINTR; } frag->frag_dead = true; -- 2.20.1