isdnloop: use strlcpy() instead of strcpy()

These strings come from a copy_from_user() and there is no way to be
sure they are NUL terminated.

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

drivers/isdn/isdnloop/isdnloop.c

@@ -1083,8 +1083,10 @@ isdnloop_start(isdnloop_card *card, isdnloop_sdef *sdefp)
 			spin_unlock_irqrestore(&card->isdnloop_lock, flags);
 			return -ENOMEM;
 		}
-		for (i = 0; i < 3; i++)
-			strcpy(card->s0num[i], sdef.num[i]);
+		for (i = 0; i < 3; i++) {
+			strlcpy(card->s0num[i], sdef.num[i],
+				sizeof(card->s0num[0]));
+		}
 		break;
 	case ISDN_PTYPE_1TR6:
 		if (isdnloop_fake(card, "DRV1.04TC-1TR6-CAPI-CNS-BASIS-29.11.95",
@@ -1097,7 +1099,7 @@ isdnloop_start(isdnloop_card *card, isdnloop_sdef *sdefp)
 			spin_unlock_irqrestore(&card->isdnloop_lock, flags);
 			return -ENOMEM;
 		}
-		strcpy(card->s0num[0], sdef.num[0]);
+		strlcpy(card->s0num[0], sdef.num[0], sizeof(card->s0num[0]));
 		card->s0num[1][0] = '\0';
 		card->s0num[2][0] = '\0';
 		break;