[ldns-users] Critical bug in ldns core lookup

[Henri Asseily]

Hi there,
first post here, and sorry if this is a dupe.

I am the CTO of Telnic.org, the registry for the new TLD ".tel".
.tel uses the DNS much more heavily than any other TLD, and especially  
the NAPTR, TXT and LOC records. In testing my iphone applications with  
ldns (that was a mess to compile for, but the subject of another  
post), I have found a critical bug when handling large record sets.

To see what I mean, simply run:

drill henri.tel NAPTR IN

This, expectedly, will tell you the answer is truncated because the  
answer is larger than 512 bytes.
Now if you try again in TCP mode or with a larger EDNS0 buffer, you  
will get bus errors.

Another domain that almost always fails is vignes.vip.tel

I'll keep digging, but now I'm 100% certain it's a bug in the core of  
ldns as this failure happens on iphone, OS X, etc... with any app  
using ldns.

More as I find it.

---
Henri Asseily
henri.tel