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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 3BDC5C32788 for ; Thu, 11 Oct 2018 15:48:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F167C2085B for ; Thu, 11 Oct 2018 15:47:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="K0K3B/XV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F167C2085B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731966AbeJKXPn (ORCPT ); Thu, 11 Oct 2018 19:15:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:49322 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726727AbeJKXPn (ORCPT ); Thu, 11 Oct 2018 19:15:43 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 539EB2098A; Thu, 11 Oct 2018 15:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539272876; bh=3e9j3LzU2eVbbwbY4xJWGkiJxsMpleI0UAcxW1/++oc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K0K3B/XVTmTlnGHfM2Gj7P0a9Jl5HH4LFqhABXAMRo2O+HVMwQfDCOCrcPJr5CkK7 Wg0Mubw6f4wJnNf8/HUPR98n3zjxS6KkSShyOrBdZFAf9XhrhOsuJYaQDDyYE6Emwi VVbEvMnjwr1l5+U96yZqntJGOSIpUhZoN0YJBvDI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Mike Snitzer Subject: [PATCH 4.18 25/44] dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer Date: Thu, 11 Oct 2018 17:40:03 +0200 Message-Id: <20181011152453.538311351@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181011152452.571669983@linuxfoundation.org> References: <20181011152452.571669983@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit b592211c33f745af67a3271ce77c10fc1e6d6241 upstream. Commit e8f74a0f0011 ("dm mpath: eliminate need to use scsi_device_from_queue") introduced 2 regressions: 1) memory leak occurs if attached_handler_name is not assigned to m->hw_handler_name 2) m->hw_handler_name can become a dangling pointer if the RETAIN_ATTACHED_HW_HANDLER flag is set and scsi_dh_attach() returns -EBUSY. Fix both of these by clearing 'attached_handler_name' pointer passed to setup_scsi_dh() after it is assigned to m->hw_handler_name. And if setup_scsi_dh() doesn't consume 'attached_handler_name' parse_path() will kfree() it. Fixes: e8f74a0f0011 ("dm mpath: eliminate need to use scsi_device_from_queue") Cc: stable@vger.kernel.org # 4.16+ Reported-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-mpath.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -806,19 +806,19 @@ static int parse_path_selector(struct dm } static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, - const char *attached_handler_name, char **error) + const char **attached_handler_name, char **error) { struct request_queue *q = bdev_get_queue(bdev); int r; if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) { retain: - if (attached_handler_name) { + if (*attached_handler_name) { /* * Clear any hw_handler_params associated with a * handler that isn't already attached. */ - if (m->hw_handler_name && strcmp(attached_handler_name, m->hw_handler_name)) { + if (m->hw_handler_name && strcmp(*attached_handler_name, m->hw_handler_name)) { kfree(m->hw_handler_params); m->hw_handler_params = NULL; } @@ -830,7 +830,8 @@ retain: * handler instead of the original table passed in. */ kfree(m->hw_handler_name); - m->hw_handler_name = attached_handler_name; + m->hw_handler_name = *attached_handler_name; + *attached_handler_name = NULL; } } @@ -867,7 +868,7 @@ static struct pgpath *parse_path(struct struct pgpath *p; struct multipath *m = ti->private; struct request_queue *q; - const char *attached_handler_name; + const char *attached_handler_name = NULL; /* we need at least a path arg */ if (as->argc < 1) { @@ -890,7 +891,7 @@ static struct pgpath *parse_path(struct attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); if (attached_handler_name || m->hw_handler_name) { INIT_DELAYED_WORK(&p->activate_path, activate_path_work); - r = setup_scsi_dh(p->path.dev->bdev, m, attached_handler_name, &ti->error); + r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error); if (r) { dm_put_device(ti, p->path.dev); goto bad; @@ -905,6 +906,7 @@ static struct pgpath *parse_path(struct return p; bad: + kfree(attached_handler_name); free_pgpath(p); return ERR_PTR(r); }