From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753513Ab2IGPb2 (ORCPT ); Fri, 7 Sep 2012 11:31:28 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:50881 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753037Ab2IGPbX (ORCPT ); Fri, 7 Sep 2012 11:31:23 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org Cc: target-devel@vger.kernel.org, nab@linux-iscsi.org, hch@lst.de, roland@kernel.org Subject: [PATCH 08/11] target: fix truncation of mode data, support zero allocation length Date: Fri, 7 Sep 2012 17:30:39 +0200 Message-Id: <1347031842-2531-9-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.7.11.2 In-Reply-To: <1347031842-2531-1-git-send-email-pbonzini@redhat.com> References: <1347031842-2531-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The offset was not bumped back to the full size after writing the header of the MODE SENSE response, so the last 1 or 2 bytes were not copied. On top of this, support zero-length requests by checking for the return value of transport_kmap_data_sg. Testcase: sg_raw -r20 /dev/sdb 5a 00 0a 00 00 00 00 00 14 00 last byte should be 0x1e it is 0x00 without the patch it is correct with the patch Signed-off-by: Paolo Bonzini --- drivers/target/target_core_spc.c | 17 +++++++---------- 1 files changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 647e51b..96e5c48 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -784,7 +784,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd) unsigned char *rbuf; int type = dev->transport->get_device_type(dev); int ten = (cmd->t_task_cdb[0] == MODE_SENSE_10); - int offset = ten ? 8 : 4; + u32 offset = ten ? 8 : 4; int length = 0; unsigned char buf[SE_MODE_PAGE_BUF]; @@ -817,6 +817,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd) offset -= 2; buf[0] = (offset >> 8) & 0xff; buf[1] = offset & 0xff; + offset += 2; if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) || (cmd->se_deve && @@ -826,13 +827,10 @@ static int spc_emulate_modesense(struct se_cmd *cmd) if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) && (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0)) spc_modesense_dpofua(&buf[3], type); - - if ((offset + 2) > cmd->data_length) - offset = cmd->data_length; - } else { offset -= 1; buf[0] = offset & 0xff; + offset += 1; if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) || (cmd->se_deve && @@ -842,14 +840,13 @@ static int spc_emulate_modesense(struct se_cmd *cmd) if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) && (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0)) spc_modesense_dpofua(&buf[2], type); - - if ((offset + 1) > cmd->data_length) - offset = cmd->data_length; } rbuf = transport_kmap_data_sg(cmd); - memcpy(rbuf, buf, offset); - transport_kunmap_data_sg(cmd); + if (rbuf) { + memcpy(rbuf, buf, min(offset, cmd->data_length)); + transport_kunmap_data_sg(cmd); + } target_complete_cmd(cmd, GOOD); return 0; -- 1.7.1