From patchwork Fri Aug 14 04:59:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Spencer Baugh X-Patchwork-Id: 7012211 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D2B79C05AC for ; Fri, 14 Aug 2015 05:01:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1F451207C7 for ; Fri, 14 Aug 2015 05:01:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36A46207C6 for ; Fri, 14 Aug 2015 05:01:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751622AbbHNFA7 (ORCPT ); Fri, 14 Aug 2015 01:00:59 -0400 Received: from catern.com ([104.131.201.120]:42855 "EHLO mail.catern.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750728AbbHNFA6 (ORCPT ); Fri, 14 Aug 2015 01:00:58 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.catern.com (Postfix) with ESMTPSA id D2CED47F67; Fri, 14 Aug 2015 05:00:56 +0000 (UTC) From: Spencer Baugh To: "Nicholas A. Bellinger" , linux-scsi@vger.kernel.org (open list:TARGET SUBSYSTEM), target-devel@vger.kernel.org (open list:TARGET SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Cc: Joern Engel , Spencer Baugh , Roland Dreier , Spencer Baugh Subject: [PATCH v2] target: Fix handling of small allocation lengths in REPORT LUNS Date: Thu, 13 Aug 2015 21:59:19 -0700 Message-Id: <1439528359-32351-1-git-send-email-sbaugh@catern.com> In-Reply-To: <1439508184.31978.57.camel@haakon3.risingtidesystems.com> References: <1439508184.31978.57.camel@haakon3.risingtidesystems.com> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Roland Dreier REPORT LUNS should not fail just because the allocation length is less than 16. The relevant section of SPC-4 is: 4.2.5.6 Allocation length The ALLOCATION LENGTH field specifies the maximum number of bytes or blocks that an application client has allocated in the Data-In Buffer. The ALLOCATION LENGTH field specifies bytes unless a different requirement is stated in the command definition. An allocation length of zero specifies that no data shall be transferred. This condition shall not be considered an error. So we should just truncate our response rather than return an error. Signed-off-by: Roland Dreier Signed-off-by: Spencer Baugh --- drivers/target/target_core_spc.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index da6130a..43a27bf 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -1210,17 +1210,13 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd) struct se_dev_entry *deve; struct se_session *sess = cmd->se_sess; struct se_node_acl *nacl; + struct scsi_lun slun; unsigned char *buf; u32 lun_count = 0, offset = 8; - - if (cmd->data_length < 16) { - pr_warn("REPORT LUNS allocation length %u too small\n", - cmd->data_length); - return TCM_INVALID_CDB_FIELD; - } + __be32 len; buf = transport_kmap_data_sg(cmd); - if (!buf) + if (cmd->data_length && !buf) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; /* @@ -1241,10 +1237,12 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd) * See SPC2-R20 7.19. */ lun_count++; - if ((offset + 8) > cmd->data_length) + if (offset >= cmd->data_length) continue; - int_to_scsilun(deve->mapped_lun, (struct scsi_lun *)&buf[offset]); + int_to_scsilun(deve->mapped_lun, &slun); + memcpy(buf + offset, &slun, + min(8u, cmd->data_length - offset)); offset += 8; } rcu_read_unlock(); @@ -1257,16 +1255,18 @@ done: * If no LUNs are accessible, report virtual LUN 0. */ if (lun_count == 0) { - int_to_scsilun(0, (struct scsi_lun *)&buf[offset]); + int_to_scsilun(0, &slun); + if (cmd->data_length > 8) + memcpy(buf + offset, &slun, + min(8u, cmd->data_length - offset)); lun_count = 1; } - lun_count *= 8; - buf[0] = ((lun_count >> 24) & 0xff); - buf[1] = ((lun_count >> 16) & 0xff); - buf[2] = ((lun_count >> 8) & 0xff); - buf[3] = (lun_count & 0xff); - transport_kunmap_data_sg(cmd); + if (buf) { + len = cpu_to_be32(lun_count * 8); + memcpy(buf, &len, min_t(int, sizeof len, cmd->data_length)); + transport_kunmap_data_sg(cmd); + } target_complete_cmd_with_length(cmd, GOOD, 8 + lun_count * 8); return 0;