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 C44F6C2BB55 for ; Thu, 16 Apr 2020 15:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A077B214D8 for ; Thu, 16 Apr 2020 15:17:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587050230; bh=auqJTuhnImmvDb6H+sMUIzlvMxOs3HGqAdeRAdKYAU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Yzow0o2Rry/ONrxcqTGUlr7UTuHUDUhHpI0roDzU4rbjf8xKuJALZZ5UrezuoEMN+ ld1fhwEiLMa/IxRfuQgpH9QwEvN4s3iNCV4LdjOxKKzBwLb+OxekRRtkgpIvlmyZCS f7Q1ntDaSldsJwxA95TviVBk93w8saj1Vlc5cBwI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441726AbgDPPRJ (ORCPT ); Thu, 16 Apr 2020 11:17:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:35080 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2898810AbgDPNtE (ORCPT ); Thu, 16 Apr 2020 09:49:04 -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 18EB120732; Thu, 16 Apr 2020 13:49:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044943; bh=auqJTuhnImmvDb6H+sMUIzlvMxOs3HGqAdeRAdKYAU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EmwCnnChByk15E/xLhyDfiC/99mAvwYknOHsQ/6G8xuDSDsIlbJLmmf6xg2gAlIDA E9IBfbyVnyPskJHXmb4FEqGJjWPmYpo8heDaVM5OkvP6Qw6V/BJbaEW0Zq6SoGwRO6 n26ZUKdXnbc83W6yCXqYS1CXjHIid45ELkwSII+A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikos Tsironis , Mike Snitzer Subject: [PATCH 5.4 164/232] dm clone: Add overflow check for number of regions Date: Thu, 16 Apr 2020 15:24:18 +0200 Message-Id: <20200416131335.527671917@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131316.640996080@linuxfoundation.org> References: <20200416131316.640996080@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 @@ -1775,6 +1775,7 @@ 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; @@ -1816,7 +1817,16 @@ 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)