isdnloop: use strlcpy() instead of strcpy()

[ Upstream commit f9a23c84 ]

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>
Signed-off-by: Willy Tarreau <w@1wt.eu>

drivers/isdn/isdnloop/isdnloop.c

@@ -1082,8 +1082,10 @@ 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",
@@ -1096,7 +1098,7 @@ 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;