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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 0F9F6C61CE4 for ; Sat, 19 Jan 2019 17:16:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDDFE2084C for ; Sat, 19 Jan 2019 17:16:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728680AbfASRP5 (ORCPT ); Sat, 19 Jan 2019 12:15:57 -0500 Received: from bout01.mta.xmission.com ([166.70.11.15]:37630 "EHLO bout01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726679AbfASRP4 (ORCPT ); Sat, 19 Jan 2019 12:15:56 -0500 Received: from mx04.mta.xmission.com ([166.70.13.214]) by bout01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1gkuDq-0004zh-LR; Sat, 19 Jan 2019 10:15:54 -0700 Received: from plesk14-shared.xmission.com ([166.70.198.161] helo=plesk14.xmission.com) by mx04.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1gkuDq-0001yC-4t; Sat, 19 Jan 2019 10:15:54 -0700 Received: from hacktheplanet (unknown [73.58.156.101]) by plesk14.xmission.com (Postfix) with ESMTPSA id F30372138AF; Sat, 19 Jan 2019 17:15:52 +0000 (UTC) Date: Sat, 19 Jan 2019 12:15:50 -0500 From: Scott Bauer To: David Kozub Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, hch@infradead.org, jonathan.derrick@intel.com Message-ID: <20190119171550.GB12171@hacktheplanet> References: <1547760716-7304-12-git-send-email-zub@linux.fjfi.cvut.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1547760716-7304-12-git-send-email-zub@linux.fjfi.cvut.cz> User-Agent: Mutt/1.9.4 (2018-02-28) X-XM-SPF: eid=1gkuDq-0001yC-4t;;;mid=<20190119171550.GB12171@hacktheplanet>;;;hst=mx04.mta.xmission.com;;;ip=166.70.198.161;;;frm=sbauer@plzdonthack.me;;;spf=none X-SA-Exim-Connect-IP: 166.70.198.161 X-SA-Exim-Mail-From: sbauer@plzdonthack.me Subject: Re: [PATCH v2 11/16] block: sed-opal: ioctl for writing to shadow mbr X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on mx04.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 17, 2019 at 09:31:51PM +0000, David Kozub wrote: > +static int write_shadow_mbr(struct opal_dev *dev, void *data) > +{ > + struct opal_shadow_mbr *shadow = data; > + const u8 __user *src; > + u8 *dst; > + size_t off = 0; > + u64 len; > + int err = 0; > + > + /* do the actual transmission(s) */ > + src = (u8 *) shadow->data; > + while (off < shadow->size) { > + err = cmd_start(dev, opaluid[OPAL_MBR], opalmethod[OPAL_SET]); > + add_token_u8(&err, dev, OPAL_STARTNAME); > + add_token_u8(&err, dev, OPAL_WHERE); > + add_token_u64(&err, dev, shadow->offset + off); > + add_token_u8(&err, dev, OPAL_ENDNAME); > + > + add_token_u8(&err, dev, OPAL_STARTNAME); > + add_token_u8(&err, dev, OPAL_VALUES); > + > + /* > + * The bytestring header is either 1 or 2 bytes, so assume 2. > + * There also needs to be enough space to accommodate the > + * trailing OPAL_ENDNAME (1 byte) and tokens added by > + * cmd_finalize. > + */ > + len = min(remaining_size(dev) - (2+1+CMD_FINALIZE_BYTES_NEEDED), > + (size_t)(shadow->size - off)); What if remaining_size(dev) < 2 + 1 + CMD_FINALIZE_BYTES_NEEDED? If that's possible we get min(UINT_MAX(ish) , some size larger than our remaining buffer) and that's not good. > + pr_debug("MBR: write bytes %zu+%llu/%llu\n", > + off, len, shadow->size); > + > + dst = add_bytestring_header(&err, dev, len); > + if (!dst) > + break; > + if (copy_from_user(dst, src + off, len)) > + err = -EFAULT; > -- > 2.20.1 > >