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authorDan Carpenter <dan.carpenter@oracle.com>2017-08-30 16:30:35 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2017-08-31 05:06:20 +0300
commite6f77540c067b48dee10f1e33678415bfcc89017 (patch)
tree61834b8b55fec5959bd84c127eb9814b39afe340 /drivers/scsi
parent0208eeaa650c5c866a3242201678a19e6dc4a14e (diff)
downloadlinux-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>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/qla2xxx/qla_attr.c8
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);