oss-security - Re: [Security] CVE request: kernel: taskstats/procfs io infoleak (was: taskstats authorized

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Date: Wed, 29 Jun 2011 22:08:05 +0400
From: Vasiliy Kulikov <segoon@...nwall.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	oss-security@...ts.openwall.com, security@...nel.org
Subject: Re: [Security] CVE request: kernel: taskstats/procfs io infoleak
 (was: taskstats authorized_keys presence infoleak PoC)

On Wed, Jun 29, 2011 at 22:03 +0400, Vasiliy Kulikov wrote:
> Now the attacker has to increment the fake password length (incrementing
> the resulted read_characters of the dead login task) and wait for
> the successful victim's login.  After ~log2(1024) tries (binary search)
> he learns precise password length.

Not log2(1024), but log2(passlen).  It doesn't matter, actually.

Also if constants are unknown, it still allows to know the delta between
old and new password lengthes on user password change.


-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments

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