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>
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index e831e01..849ff810 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -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: