From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752391AbdKVCXE (ORCPT ); Tue, 21 Nov 2017 21:23:04 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56722 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751451AbdKVCUg (ORCPT ); Tue, 21 Nov 2017 21:20:36 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Martin K. Petersen" , "Dan Carpenter" , "shqking" Date: Wed, 22 Nov 2017 01:58:13 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 070/133] scsi: qla2xxx: Fix an integer overflow in sysfs code In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit e6f77540c067b48dee10f1e33678415bfcc89017 upstream. The value of "size" comes from the user. When we add "start + size" it could lead to an integer overflow bug. It means we vmalloc() a lot more memory than we had intended. I believe that on 64 bit systems vmalloc() can succeed even if we ask it to allocate huge 4GB buffers. So we would get memory corruption and likely a crash when we call ha->isp_ops->write_optrom() and ->read_optrom(). Only root can trigger this bug. Link: https://bugzilla.kernel.org/show_bug.cgi?id=194061 Fixes: b7cc176c9eb3 ("[SCSI] qla2xxx: Allow region-based flash-part accesses.") Reported-by: shqking Signed-off-by: Dan Carpenter Signed-off-by: Martin K. Petersen Signed-off-by: Ben Hutchings --- drivers/scsi/qla2xxx/qla_attr.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/scsi/qla2xxx/qla_attr.c +++ b/drivers/scsi/qla2xxx/qla_attr.c @@ -396,6 +396,8 @@ qla2x00_sysfs_write_optrom_ctl(struct fi return -EINVAL; if (start > ha->optrom_size) return -EINVAL; + if (size > ha->optrom_size - start) + size = ha->optrom_size - start; mutex_lock(&ha->optrom_mutex); switch (val) { @@ -421,8 +423,7 @@ qla2x00_sysfs_write_optrom_ctl(struct fi } ha->optrom_region_start = start; - ha->optrom_region_size = start + size > ha->optrom_size ? - ha->optrom_size - start : size; + ha->optrom_region_size = start + size; ha->optrom_state = QLA_SREADING; ha->optrom_buffer = vmalloc(ha->optrom_region_size); @@ -494,8 +495,7 @@ qla2x00_sysfs_write_optrom_ctl(struct fi } ha->optrom_region_start = start; - ha->optrom_region_size = start + size > ha->optrom_size ? - ha->optrom_size - start : size; + ha->optrom_region_size = start + size; ha->optrom_state = QLA_SWRITING; ha->optrom_buffer = vmalloc(ha->optrom_region_size);