netdev - Re: Incorrect source IP address on IGMP membership report

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20171209222008.GA11133@lunn.ch>
Date:   Sat, 9 Dec 2017 23:20:08 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     Kevin Cernekee <cernekee@...omium.org>
Cc:     netdev@...r.kernel.org
Subject: Re: Incorrect source IP address on IGMP membership report

> Hmm, RFC3376 says:
> 
> 4.2.13. IP Source Addresses for Reports
> 
>    An IGMP report is sent with a valid IP source address for the
>    destination subnet.  The 0.0.0.0 source address may be used by a
>    system that has not yet acquired an IP address.  Note that the
>    0.0.0.0 source address may simultaneously be used by multiple systems
>    on a LAN.  Routers MUST accept a report with a source address of
>    0.0.0.0.
> 
> Would it make sense to add a special case that says "zero out
> pip->saddr if the interface doesn't have any IPv4 addresses"?  e.g.

Yes, this looks O.K. for IGMPv3.

     Andrew