From: Michael Opdenacker <michael-lists@free-electrons.com>
To: "linux-os (Dick Johnson)" <linux-os@analogic.com>,
chase.venters@clientec.com
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Option to clear allocated kernel memory before freeing it?
Date: Mon, 19 Jun 2006 22:12:18 +0200 [thread overview]
Message-ID: <44970522.9030404@free-electrons.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0606191145470.4384@chaos.analogic.com>
Chase, Dick,
> No. Memory is cleared before being mapped to user-space. Memory
> that is allocated for use by the kernel is never cleared by default.
> To do so would waste valuable time for nothing gained.
>
>
>> Unless I'm missing something, uncleared memory previously used for
>> kernel allocations could later be recycled for user allocations, making
>> it possible for a user program to access sensitive driver data if it's
>> lucky.
>>
>
> Wrong. You are missing a lot.
>
Oops, I realize I was really missing a lot! Thank you very much for
leading me to the right path!
Cheers,
Michael.
--
Michael Opdenacker, Free Electrons
Free Embedded Linux Training Materials
on http://free-electrons.com/training
(More than 1000 pages!)..
prev parent reply other threads:[~2006-06-19 20:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-19 14:48 Option to clear allocated kernel memory before freeing it? Michael Opdenacker
2006-06-19 15:32 ` Chase Venters
2006-06-19 15:51 ` linux-os (Dick Johnson)
2006-06-19 20:12 ` Michael Opdenacker [this message]
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