isdn: make sure strings are null terminated

These strings come from the user.  We strcpy() them inside
cf_command() so we should check that they are NULL terminated and
return an error if not.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/isdn/divert/divert_procfs.c b/drivers/isdn/divert/divert_procfs.c
index 33ec9e4677727800d5439e16300be820c92090b8..9021182c4b766e02454365f1e2b6d22822358f8a 100644 (file)
--- a/drivers/isdn/divert/divert_procfs.c
+++ b/drivers/isdn/divert/divert_procfs.c
@@ -242,6 +242,12 @@ static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
                case IIOCDOCFINT:
                        if (!divert_if.drv_to_name(dioctl.cf_ctrl.drvid))
                                return (-EINVAL);       /* invalid driver */
+                       if (strnlen(dioctl.cf_ctrl.msn, sizeof(dioctl.cf_ctrl.msn)) ==
+                                       sizeof(dioctl.cf_ctrl.msn))
+                               return -EINVAL;
+                       if (strnlen(dioctl.cf_ctrl.fwd_nr, sizeof(dioctl.cf_ctrl.fwd_nr)) ==
+                                       sizeof(dioctl.cf_ctrl.fwd_nr))
+                               return -EINVAL;
                        if ((i = cf_command(dioctl.cf_ctrl.drvid,
                                            (cmd == IIOCDOCFACT) ? 1 : (cmd == IIOCDOCFDIS) ? 0 : 2,
                                            dioctl.cf_ctrl.cfproc,