scsi: sg: check length passed to SG_NEXT_CMD_LEN

The user can control the size of the next command passed along, but the
value passed to the ioctl isn't checked against the usable max command
size.

Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Chang <dpf@google.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
peter chang 2017-02-15 14:11:54 -08:00 committed by Martin K. Petersen
parent 645b8ef594
commit bf33f87dd0

View file

@ -996,6 +996,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
result = get_user(val, ip);
if (result)
return result;
if (val > SG_MAX_CDB_SIZE)
return -ENOMEM;
sfp->next_cmd_len = (val > 0) ? val : 0;
return 0;
case SG_GET_VERSION_NUM: