| From: Dan Carpenter <dan.carpenter@oracle.com> |
| Date: Wed, 30 Aug 2017 16:30:35 +0300 |
| Subject: scsi: qla2xxx: Fix an integer overflow in sysfs code |
| |
| 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 <shqking@gmail.com> |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| 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); |