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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 2CB9DC10F0E for ; Mon, 15 Apr 2019 19:15:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFD9E218D3 for ; Mon, 15 Apr 2019 19:15:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355713; bh=g6g8xW5j/YIu+0VLQs8Xd3m2QqFGLBL2VMlWFkNdXjA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BCW9QFBPaTJHb6vh4vSs5mS3WvLupjmBH8CFf+lB07VeO9iPhEOiAmTOSEOoWC0K4 L+uNatmealpEJon4TLyEl/lWMi6DktIsQAPszy7djhB0AjZLGnDr9WUfQcEyLAbcxQ HcgPRu+plpMzzfv41Yrf98EPuHtze7TzwozB+sgQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731722AbfDOTOT (ORCPT ); Mon, 15 Apr 2019 15:14:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:52456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731696AbfDOTOQ (ORCPT ); Mon, 15 Apr 2019 15:14:16 -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 AC338218EA; Mon, 15 Apr 2019 19:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355656; bh=g6g8xW5j/YIu+0VLQs8Xd3m2QqFGLBL2VMlWFkNdXjA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jSkX8AfSptdvr9cfPk1INCeB4x14j88xB0llHMfr1ri3kDioGVtsE/QW6QY4ObSz+ 7e5xsgSk3qCa49++h3yjm2C0Oz0wvnBkY/cTr7B6FnYuYngWdVB0QkgEXMFSJwEZlT WZvAO24qyIk/vj24KmuIK5+uF8+vdBwTbnK7xP1U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer Subject: [PATCH 5.0 110/117] dm integrity: change memcmp to strncmp in dm_integrity_ctr Date: Mon, 15 Apr 2019 21:01:20 +0200 Message-Id: <20190415183750.345852297@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183744.887851196@linuxfoundation.org> References: <20190415183744.887851196@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: Mikulas Patocka commit 0d74e6a3b6421d98eeafbed26f29156d469bc0b5 upstream. If the string opt_string is small, the function memcmp can access bytes that are beyond the terminating nul character. In theory, it could cause segfault, if opt_string were located just below some unmapped memory. Change from memcmp to strncmp so that we don't read bytes beyond the end of the string. Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-integrity.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -3185,7 +3185,7 @@ static int dm_integrity_ctr(struct dm_ta journal_watermark = val; else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1) sync_msec = val; - else if (!memcmp(opt_string, "meta_device:", strlen("meta_device:"))) { + else if (!strncmp(opt_string, "meta_device:", strlen("meta_device:"))) { if (ic->meta_dev) { dm_put_device(ti, ic->meta_dev); ic->meta_dev = NULL; @@ -3204,17 +3204,17 @@ static int dm_integrity_ctr(struct dm_ta goto bad; } ic->sectors_per_block = val >> SECTOR_SHIFT; - } else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) { + } else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) { r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error, "Invalid internal_hash argument"); if (r) goto bad; - } else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) { + } else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) { r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error, "Invalid journal_crypt argument"); if (r) goto bad; - } else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) { + } else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) { r = get_alg_and_key(opt_string, &ic->journal_mac_alg, &ti->error, "Invalid journal_mac argument"); if (r)