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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 59044C2BB55 for ; Thu, 16 Apr 2020 13:57:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EFCC2076D for ; Thu, 16 Apr 2020 13:57:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587045458; bh=rYEbbTZpOvYM3lyWTrWeTlys/rHzSaPGXH+mvSyaYi8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YQWR91n3fWjbdKBsODlHymy4AmhqmhkYdvXfbuUzX9z+z6hYHVyCDFHpJpLIh8aCx QUjH4/b/5q7XE9apt7PPO0uRYENPSQhidE7nScCioGJPwG9Dd2Q2et5nRBY8XaC6iW WDM4yRTkR5R6LN8azDNNbjJ2vNeNpajYxU+at4v8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2506727AbgDPN5g (ORCPT ); Thu, 16 Apr 2020 09:57:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:51666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2897931AbgDPNjS (ORCPT ); Thu, 16 Apr 2020 09:39:18 -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 B2AC421BE5; Thu, 16 Apr 2020 13:39:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044358; bh=rYEbbTZpOvYM3lyWTrWeTlys/rHzSaPGXH+mvSyaYi8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PRp9yvR+QbyQqA4XsLuEB8LdG4Hy47ey6TpbT9sGh/G7tYqQ+z0O0aaOkpbdD3mms a56qJd2Ng/qDPn60rPOxn1PR3VPSDZlghzSu8+9ceGPQ2DBMsWcxnfz1hdLF6k9+K3 CYz5+XwN9r1sxK4kfNxaEe3VXdplCqqQaAL/T4D4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikos Tsironis , Mike Snitzer Subject: [PATCH 5.5 185/257] dm clone: Add overflow check for number of regions Date: Thu, 16 Apr 2020 15:23:56 +0200 Message-Id: <20200416131349.450708706@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.891903893@linuxfoundation.org> References: <20200416131325.891903893@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: Nikos Tsironis commit cd481c12269b4d276f1a52eda0ebd419079bfe3a upstream. Add overflow check for clone->nr_regions variable, which holds the number of regions of the target. The overflow can occur with sufficiently large devices, if BITS_PER_LONG == 32. E.g., if the region size is 8 sectors (4K), the overflow would occur for device sizes > 34359738360 sectors (~16TB). This could result in multiple device sectors wrongly mapping to the same region number, due to the truncation from 64 bits to 32 bits, which would lead to data corruption. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-clone-target.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/md/dm-clone-target.c +++ b/drivers/md/dm-clone-target.c @@ -1790,6 +1790,7 @@ error: static int clone_ctr(struct dm_target *ti, unsigned int argc, char **argv) { int r; + sector_t nr_regions; struct clone *clone; struct dm_arg_set as; @@ -1831,7 +1832,16 @@ static int clone_ctr(struct dm_target *t goto out_with_source_dev; clone->region_shift = __ffs(clone->region_size); - clone->nr_regions = dm_sector_div_up(ti->len, clone->region_size); + nr_regions = dm_sector_div_up(ti->len, clone->region_size); + + /* Check for overflow */ + if (nr_regions != (unsigned long)nr_regions) { + ti->error = "Too many regions. Consider increasing the region size"; + r = -EOVERFLOW; + goto out_with_source_dev; + } + + clone->nr_regions = nr_regions; r = validate_nr_regions(clone->nr_regions, &ti->error); if (r)