From patchwork Tue May 26 18:52:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 225389 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, 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 24FA1C433DF for ; Tue, 26 May 2020 19:03:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5AC621475 for ; Tue, 26 May 2020 19:03:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519799; bh=/E1gjTXH8TUAn0tdJdqEaHfqZRnnrnwDEH0bruPbu3s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VgOA3lb4j6hDov3Huuq7Al/roz/xWF6gFq2xj0ieZOajDbuoA21/4CHxaDJ9XEAuh CY1x0eTLTdzDWUpiO5Kj6JvHwxBj8ujM6hqE35eVqmIOgTD3Lmln/HUlSmT7qkTGWg JYOo1JMQvfVB/HMOl7kXZ/mx9K4SvTtdCRHNlAsg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390625AbgEZTDS (ORCPT ); Tue, 26 May 2020 15:03:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:58494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391184AbgEZTDR (ORCPT ); Tue, 26 May 2020 15:03:17 -0400 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 9C9A92086A; Tue, 26 May 2020 19:03:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519797; bh=/E1gjTXH8TUAn0tdJdqEaHfqZRnnrnwDEH0bruPbu3s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sTifHLpwbO1sz3bRV6+rPVUnIJnJgBX/g/QOE2ilaDQTxWhPAP0hZOMThedB6sobi UrP/14RRTtJMF9O9C50cD1NlpeOGheIHVUmSpiUIiYjTCZNmd+eyQgVldvsIpyvI7Y TXYdJV2hffCs4BgZaH6RZ9H9k6axKWAXNVL7An0o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , Christoph Hellwig , Sasha Levin Subject: [PATCH 4.19 21/81] configfs: fix config_item refcnt leak in configfs_rmdir() Date: Tue, 26 May 2020 20:52:56 +0200 Message-Id: <20200526183929.132351497@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183923.108515292@linuxfoundation.org> References: <20200526183923.108515292@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 2cc6b1c49d34..f9628fc20fec 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;