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 E1025C433E0 for ; Mon, 29 Jun 2020 19:55:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1F9020674 for ; Mon, 29 Jun 2020 19:55:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593460503; bh=3cOiptvMgCO/QJO7RSsbOX4c0Fd17ZHS8ude4fJCyoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ABXXL//jZoxatM5v7iW9PZ88jUURdDjZNA4ZK5oAtt9RZF3QRsWumBeOjUe3imKSO yplY00ScnsEGKuSpPrD00WYTV5+i1UEyb+/pSy91Ktj0DzumKfICq1ImavtrLMKNXw /fMZXZWdA3iCrpwFa80sQLe6qy5S5Ok41akYfRzU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388243AbgF2TzB (ORCPT ); Mon, 29 Jun 2020 15:55:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:47666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387665AbgF2TkZ (ORCPT ); Mon, 29 Jun 2020 15:40:25 -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 2FA4B24877; Mon, 29 Jun 2020 15:26:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593444374; bh=3cOiptvMgCO/QJO7RSsbOX4c0Fd17ZHS8ude4fJCyoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wygQyurDZYibW+ZBC1W8BC/JiIWgAmu9WfQCLmppIZxxBjvkx3fgjObIyldtF9a1M 0qIdJQmbsB3skkVx0xTtXdZ15xTf3KZVQDl0slaw9I/acHZHWH23iFytGLv3OZhjXz HaBPlvIkWPb+YFhmRDoDfkpto0IRap8TTbu/zROs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiyu Yang , Xin Tan , Steve French , Greg Kroah-Hartman Subject: [PATCH 5.4 051/178] cifs: Fix cached_fid refcnt leak in open_shroot Date: Mon, 29 Jun 2020 11:23:16 -0400 Message-Id: <20200629152523.2494198-52-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629152523.2494198-1-sashal@kernel.org> References: <20200629152523.2494198-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.4.50-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.4.50-rc1 X-KernelTest-Deadline: 2020-07-01T15:25+00:00 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 commit 77577de64167aa0643d47ffbaacf3642632b321b upstream. open_shroot() invokes kref_get(), which increases the refcount of the "tcon->crfid" object. When open_shroot() returns not zero, it means the open operation failed and close_shroot() will not be called to decrement the refcount of the "tcon->crfid". The reference counting issue happens in one normal path of open_shroot(). When the cached root have been opened successfully in a concurrent process, the function increases the refcount and jump to "oshr_free" to return. However the current return value "rc" may not equal to 0, thus the increased refcount will not be balanced outside the function, causing a refcnt leak. Fix this issue by setting the value of "rc" to 0 before jumping to "oshr_free" label. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Steve French CC: Stable Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2ops.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 58915d882285c..f5e893ed48aaa 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -736,6 +736,7 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) /* close extra handle outside of crit sec */ SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); } + rc = 0; goto oshr_free; } -- 2.25.1