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=-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=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 8AC35C433DF for ; Tue, 26 May 2020 19:32:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6ADAE20776 for ; Tue, 26 May 2020 19:32:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521540; bh=sEH7FlcbtULD/jnI/XwLJzHyZ9OSJdBrQc3iYDd0vrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lDfGRpwn8thnK+2WfPb1KoroSjUfJEwheZep1F4BVKxY2d0jhfjoDv3cl/ODPtr7F HGCSBk25N2SdgdrktdPbpjwvqjx+5BL9FtAlpQAPi8MLimyVqmGgaokiQit5t5voyx ydXQNvhxSiNCsH/huXf5H583tKxi0GXhhNV2nmb4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390163AbgEZS5p (ORCPT ); Tue, 26 May 2020 14:57:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:50982 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389371AbgEZS5m (ORCPT ); Tue, 26 May 2020 14:57:42 -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 C9DB62084C; Tue, 26 May 2020 18:57:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519462; bh=sEH7FlcbtULD/jnI/XwLJzHyZ9OSJdBrQc3iYDd0vrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EwKDeeVLvpRUt+Ii2IvDzsN1tTZg+62mvOVA2ELekZFPtdKYafcXFfZBJFRzfkDrg U9dtpZxi/LXm7qsuRbmyT3TtdWmDH9vEGNJ+pssgLp/8AL3aV5d29PqyISngwLv8DI 5BM5hYzG33G8OGmuGOd6ZxqVSN9LfxIHsOb5bfeo= 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 4.9 13/64] configfs: fix config_item refcnt leak in configfs_rmdir() Date: Tue, 26 May 2020 20:52:42 +0200 Message-Id: <20200526183918.021605314@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183913.064413230@linuxfoundation.org> References: <20200526183913.064413230@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: 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 c2ef617d2f97..c875f246cb0e 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; -- 2.25.1