lkml.org 
[lkml]   [2008]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM
Rick Jones wrote:
> Is there nothing associated with the networking stack - NIC, driver,
> protocols, system calls which can be used as a source of entropy?

The issue is with being externally observable and controllable, or, with
some irq mitigation schemes, be made /too regular/.

Interrupts (or timed mitigation events) may be triggered by the outside
world, which makes it a very short path from remote attacker to local
kernel entropy pool.

Finally, with severe load, there are little or no interrupts thanks to
heavy mitigation, which means your entropy pool may be externally DoS'd.

Or at the very least, when your entropy needs to be INCREASED (due to
heavy workload due to heavy traffic), your incoming entropy DECREASES
due to decreased interrupts.

[I just realized that last one. Heck, I'm even convincing myself even
more its a bad idea]

Jeff





\
 
 \ /
  Last update: 2008-05-15 20:35    [W:0.109 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site