diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2017-08-30 16:30:35 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-08-31 05:06:20 +0300 |
| commit | e6f77540c067b48dee10f1e33678415bfcc89017 (patch) | |
| tree | 61834b8b55fec5959bd84c127eb9814b39afe340 | |
| parent | 0208eeaa650c5c866a3242201678a19e6dc4a14e (diff) | |
| download | linux-e6f77540c067b48dee10f1e33678415bfcc89017.tar.xz | |
scsi: qla2xxx: Fix an integer overflow in sysfs code
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
Cc: <stable@vger.kernel.org>
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>
| -rw-r--r-- | drivers/scsi/qla2xxx/qla_attr.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/scsi/qla2xxx/qla_attr.c b/drivers/scsi/qla2xxx/qla_attr.c index 08a1feb3a195..8c6ff1682fb1 100644 --- a/drivers/scsi/qla2xxx/qla_attr.c +++ b/drivers/scsi/qla2xxx/qla_attr.c @@ -318,6 +318,8 @@ qla2x00_sysfs_write_optrom_ctl(struct file *filp, struct kobject *kobj, 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 file *filp, struct kobject *kobj, } 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 file *filp, struct kobject *kobj, } 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); |