isdnloop: Validate NUL-terminated strings from user.
Return -EINVAL unless all of user-given strings are correctly
NUL-terminated.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c
index 02125e6..e1f8748 100644
--- a/drivers/isdn/isdnloop/isdnloop.c
+++ b/drivers/isdn/isdnloop/isdnloop.c
@@ -1070,6 +1070,12 @@
return -EBUSY;
if (copy_from_user((char *) &sdef, (char *) sdefp, sizeof(sdef)))
return -EFAULT;
+
+ for (i = 0; i < 3; i++) {
+ if (!memchr(sdef.num[i], 0, sizeof(sdef.num[i])))
+ return -EINVAL;
+ }
+
spin_lock_irqsave(&card->isdnloop_lock, flags);
switch (sdef.ptype) {
case ISDN_PTYPE_EURO: