Re: Where exactly will arch_fast_hash be used

From: Daniel Borkmann
Date: Thu Dec 04 2014 - 10:44:14 EST

On 12/04/2014 04:39 PM, Thomas Graf wrote:
On 12/04/14 at 11:29pm, Herbert Xu wrote:
On Thu, Dec 04, 2014 at 03:26:37PM +0000, Thomas Graf wrote:

As Daniel pointed out, this work originated for the OVS edge use
case where security is of less concern and the rehashing is
sufficient. Identifying collisions is less of interest as the user
space fall back provides a greater surface for an attack.

Well in that case the current setup I think is very misleading.
It's inviting unsuspecting kernel developers to use it as a hash
function for general hash tables, which AFAICS is something that
it fails at miserably.

Well, it's called fast hash and not secure hash ;-) but a clear hint
definitely wouldn't hurt.

Hm, I thought the kernel doc on arch_fast_hash() in include/linux/hash.h
would give enough of a hint ...
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