From patchwork Mon Mar 29 07:58:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 411604 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 0D963C433E3 for ; Mon, 29 Mar 2021 08:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D99F861974 for ; Mon, 29 Mar 2021 08:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232116AbhC2IGJ (ORCPT ); Mon, 29 Mar 2021 04:06:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:48450 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232191AbhC2IFO (ORCPT ); Mon, 29 Mar 2021 04:05:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 461CA6197C; Mon, 29 Mar 2021 08:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005113; bh=LCfOYbdDrWCE+GJPVozw9HGEGOggj0If07yc6i7jxEg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=APEyjRyvIEZ2TlZPGNbZS54vOxwyNQpDBX9DS6XygZlXp6G2Nm1cehjulI3Mc2Pd1 oNxgiwOHDFpPDxlV851RCF9UpyCueJM+UNBOH47/WwauuaIAw5FvJpYMhpRX9GdwZ5 UANvDgGAKhfYLf6vBvx0QM3rHJM0Go8yJoy3A+do= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Dan Carpenter , Mike Snitzer Subject: [PATCH 4.14 28/59] dm ioctl: fix out of bounds array access when no devices Date: Mon, 29 Mar 2021 09:58:08 +0200 Message-Id: <20210329075609.816700615@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075608.898173317@linuxfoundation.org> References: <20210329075608.898173317@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mikulas Patocka commit 4edbe1d7bcffcd6269f3b5eb63f710393ff2ec7a upstream. If there are not any dm devices, we need to zero the "dev" argument in the first structure dm_name_list. However, this can cause out of bounds write, because the "needed" variable is zero and len may be less than eight. Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is too small to hold the "nl->dev" value. Signed-off-by: Mikulas Patocka Reported-by: Dan Carpenter Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -529,7 +529,7 @@ static int list_devices(struct file *fil * Grab our output buffer. */ nl = orig_nl = get_result_buffer(param, param_size, &len); - if (len < needed) { + if (len < needed || len < sizeof(nl->dev)) { param->flags |= DM_BUFFER_FULL_FLAG; goto out; }