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Date: Thu, 21 Jun 2018 22:26:40 -0400
From: Rich Felker <>
To: Marco Dickert <>
Subject: Re: Bug in getaddrinfo

On Fri, Jun 22, 2018 at 12:04:31AM +0200, Marco Dickert wrote:
> Hi all.
> I found a bug in the musl implementation of getaddrinfo(). It apparently returns
> a bad ai_canonname value. I used this [1] code to produce the following results
Please attach testcases rather than linking to transient pastebins.
I've saved and attached the linked code here.

> on an alpine linux (edge):
> ----
> alpine:~# ./addrinfo-test
> Result 0 0xda051c83080
> Canonname
> alpine:~# ./addrinfo-test
> Result 0 0x53f7dac4080
> Canonname
> ----
> The problem is the trailing dot in the Commonname in the second example, which
> should not be there. See also this [2] bug report I opened in the first place.


    if the canonical name is not available, then ai_canonname shall
    refer to the nodename argument or a string with the same contents.

It's not entirely clear what "available" means, but I think it's
generally interpreted as meaning "the requested name is a CNAME".

On the other hand we already define availability for another case,
search domains, where a duplicate of the requested nodename argument
is not returned, so I think it's reasonable to make a change here too,
especially if that's what other implementations do. I'll take a look
at it.

Thanks for the report.


View attachment "addrinfo-test.c" of type "text/plain" (593 bytes)

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