netdev - Re: [PATCH] IPv4: skip loopback checksums in ip

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Mon, 19 Oct 2009 22:56:52 +0200
From:	Torsten Schmidt <torsten.schmidt@...06.tu-chemnitz.de>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Linux Netdev List <netdev@...r.kernel.org>
Subject: Re: [PATCH] IPv4: skip loopback checksums in ip_rcv()

Eric Dumazet wrotes:
> This is bogus IMHO.
> 
> One bit could be corrupted in iph, and ntohl(iph->daddr) becomes 0x7fxxyyzz,
> we then accept a bogus frame. This is a RFC violation.
> 
> This also slows down non loopback devices, adding an extra test.
> 
> ip_fast_csum() is really fast (about 16 instructions).

Yes, you are right. So it would be better to only skip csum if *dev is 
our loopback interface ? Right ?
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html