Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933718AbdIXUoe (ORCPT ); Sun, 24 Sep 2017 16:44:34 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33008 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932959AbdIXUoa (ORCPT ); Sun, 24 Sep 2017 16:44:30 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, shqking , Dan Carpenter , "Martin K. Petersen" Subject: [PATCH 4.13 072/109] scsi: qla2xxx: Fix an integer overflow in sysfs code Date: Sun, 24 Sep 2017 22:33:33 +0200 Message-Id: <20170924203355.987211466@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170924203353.104695385@linuxfoundation.org> References: <20170924203353.104695385@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2110 Lines: 62 4.13-stable 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: Greg Kroah-Hartman --- 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 @@ -318,6 +318,8 @@ 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) { @@ -343,8 +345,7 @@ 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); @@ -417,8 +418,7 @@ 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);