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=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 37C2AC433E0 for ; Tue, 9 Jun 2020 00:35:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03C7C206C3 for ; Tue, 9 Jun 2020 00:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591662942; bh=4VPdxXWjr16mx7dly3zIokwM4xa2s8mgnV64LSzfatA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Xjkgx7gH2mNRc846l0284YGFBVnAvPc3p5N5EDHnVtTHZl1QfbUcmWLMNR+feOIGl G6gM/m1vzSC9/I9sd5Gc6/VLwFw4OFVl0pLkThbh43eNgru9VTAOWGNBqo5hppmJ2j KJ+grhY8d+SsVEPJJPDFwyPuG98oDkhKR2u//tf0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730772AbgFIAfk (ORCPT ); Mon, 8 Jun 2020 20:35:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:34666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729794AbgFHXOY (ORCPT ); Mon, 8 Jun 2020 19:14:24 -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 5CE4A21501; Mon, 8 Jun 2020 23:14:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658064; bh=4VPdxXWjr16mx7dly3zIokwM4xa2s8mgnV64LSzfatA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dt5xH+95hIBLp0PK4KJOui+8gFpZtjdfaw8uP96SS4sXuhvJ1AI+dRDNQe35j3vO3 /Pjas30mClH2ei4rMvZbdv3hU/RWGamCmFQ3uWG6SF7z7JMRJdc9p0fPpZsCp6IbXV 42nLRrRlxe+18q6Mwha7wUtrywC+W4RhPmuFJA+w= 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 5.6 110/606] configfs: fix config_item refcnt leak in configfs_rmdir() Date: Mon, 8 Jun 2020 19:03:55 -0400 Message-Id: <20200608231211.3363633-110-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-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 cf7b7e1d5bd7..cb733652ecca 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1519,6 +1519,7 @@ 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