From: Manfred Spraul <manfred@colorfullife.com>
To: "David S. Miller" <davem@redhat.com>
Cc: rusty@rustcorp.com.au, linux-kernel@vger.kernel.org
Subject: Re: [TRIVIAL] Warn users about machines with non-working WP bit
Date: Tue, 06 Aug 2002 11:42:49 +0200 [thread overview]
Message-ID: <3D4F9A19.5040100@colorfullife.com> (raw)
In-Reply-To: 20020806.022813.27560736.davem@redhat.com
David S. Miller wrote:
> From: Manfred Spraul <manfred@colorfullife.com>
> Date: Tue, 06 Aug 2002 11:17:33 +0200
>
> > - printk("No.\n");
> > + printk("No (that's security hole).\n");
> > #ifdef CONFIG_X86_WP_WORKS_OK
>
> Could you explain the hole?
> WP works for user space apps, only ring0 (or ring 0-2?) code
> ignores the WP bit on i386.
>
>So copy_to_user() could write to user areas that are write-proteced.
>
>verify_area() checks aren't enough, consider a threaded application
>calling mprotect() while the copy is in progress.
>
>
Then we should either fix copy_to_user(), or mark 80386 unsupported, or
disable multi-threading on 80386. It's a random memory corruption, far
worse than a security hole.
--
Manfred
next prev parent reply other threads:[~2002-08-06 9:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-08-06 9:17 [TRIVIAL] Warn users about machines with non-working WP bit Manfred Spraul
2002-08-06 9:28 ` David S. Miller
2002-08-06 9:42 ` Manfred Spraul [this message]
2001-08-20 20:03 ` Pavel Machek
2002-08-06 14:03 ` Kasper Dupont
2002-08-06 13:56 ` David S. Miller
2002-08-06 14:16 ` Kasper Dupont
2002-08-06 14:05 ` David S. Miller
2002-08-06 14:27 ` Kasper Dupont
2002-08-06 14:36 ` Manfred Spraul
2001-08-20 20:06 ` Pavel Machek
2002-08-19 22:04 ` Alan Cox
2002-08-06 15:11 ` Kasper Dupont
2002-08-06 16:38 ` Willy Tarreau
2002-08-06 16:45 ` Zwane Mwaikambo
-- strict thread matches above, loose matches on Subject: below --
2002-08-06 3:49 Rusty Trivial Russell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3D4F9A19.5040100@colorfullife.com \
--to=manfred@colorfullife.com \
--cc=davem@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rusty@rustcorp.com.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox