linux-kernel - Re: [patch 0/5] Support for sanitization flag in low-level page allocator

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]

Message-Id: <1243689871.6645.136.camel@laptop>
Date:	Sat, 30 May 2009 15:24:31 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	pageexec@...email.hu
Cc:	"Larry H." <research@...reption.com>,
	Arjan van de Ven <arjan@...radead.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Ingo Molnar <mingo@...e.hu>, Rik van Riel <riel@...hat.com>,
	linux-kernel@...r.kernel.org, Linus Torvalds <torvalds@...l.org>,
	linux-mm@...ck.org, Ingo Molnar <mingo@...hat.com>
Subject: Re: [patch 0/5] Support for sanitization flag in low-level page
 allocator

On Sat, 2009-05-30 at 15:21 +0200, Peter Zijlstra wrote:
> On Sat, 2009-05-30 at 13:42 +0200, pageexec@...email.hu wrote:
> > > Why waste time on this?
> > 
> > e.g., when userland executes a syscall, it 'can run kernel code'. if that kernel
> > code (note: already exists, isn't provided by the attacker) gives unintended
> > kernel memory back to userland, there is a problem. that problem is addressed
> > in part by early sanitizing of freed data.
> 
> Right, so the whole point is to minimize the impact of actual bugs,
> right? So why not focus on fixing those actual bugs? Can we create tools
> to help us find such bugs faster? We use sparse for a lot of static
> checking, we create things like lockdep and kmemcheck to dynamically
> find trouble.
> 
> Can we instead of working around a problem, fix the actual problem?

Also, I'm not at all opposed to make crypto code use kzfree(). That code
knows it had sensitive data in memory, it can wipe the memory when it
frees it -- that makes perfect sense.

Wiping everything because we're too 'lazy' to figure out what really
matters otoh seems silly.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/