From: Manuel Arostegui Ramirez <manuel@todo-linux.com>
To: Nuno Monteiro <nuno@itsari.org>,
Gianni Tedesco <gianni@scaramanga.co.uk>
Cc: marcelo.tosatti@cyclades.com, linux-kernel@vger.kernel.org
Subject: Re: Local DoS attack on i386 (was: new kernel bug)
Date: Mon, 14 Jun 2004 16:59:37 +0200 [thread overview]
Message-ID: <200406141659.37844.manuel@todo-linux.com> (raw)
In-Reply-To: <20040614142001.GA3032@hobbes.itsari.int>
El Lunes 14 Junio 2004 16:20, Nuno Monteiro escribió:
> On 2004.06.14 14:58, Gianni Tedesco wrote:
> > On Sat, 2004-06-12 at 11:59 +0200, Manuel Arostegui Ramirez wrote:
> > > Somebody know a patch to solved this new bug?
> > > http://reviewed.homelinux.org/news/2004-06-11_kernel_crash/index.html.e
> > >n Affected versions:
> > > * Linux 2.6.x
> > > o Linux 2.6.7-rc2
> > > o Linux 2.6.6 (all versions)
> > > o Linux 2.6.6 SMP (verified by riven)
> > > o Linux 2.6.5-gentoo (verified by RatiX)
> > > o Linux 2.6.5-mm6 - (verified by Mariux)
> > > * Linux 2.4.2x
> > > o Linux 2.4.26 vanilla
> > > o Linux 2.4.26-rc1 vanilla
> > > o Linux 2.4.26-gentoo-r1
> > > o Linux 2.4.22
> >
> > Seems to be a scheduler race or something?
>
> This was already fixed in 2.6, see
> http://linux.bkbits.net:8080/linux-2.5/diffs/include/asm-i386/i387.h@1.16?n
>av=index.html|src/.|src/include|src/include/asm-i386|hist/include/asm-i386/i
>387.h
>
>
> The same fix should be applied to 2.4. I'm running locally a very
> hacked version of 2.4.22 with it and it survives that crash.c program.
>
> Here's the diff. Marcelo, please merge.
>
>
> ---
> linux-2.4.27-pre5/include/asm-i386/i387.h~fix-x86-clear_fpu-macro 2004-06-1
>4 15:12:13.909059344 +0100 +++
> linux-2.4.27-pre5/include/asm-i386/i387.h 2004-06-14 15:12:45.970185312
> +0100 @@ -34,7 +34,7 @@ extern void kernel_fpu_begin(void);
>
> #define clear_fpu( tsk ) do { \
> if ( tsk->flags & PF_USEDFPU ) { \
> - asm volatile("fwait"); \
> + asm volatile("fnclex ; fwait"); \
> tsk->flags &= ~PF_USEDFPU; \
> stts(); \
> } \
> -
This diff fixed the bug in 2.4.X?
Thanks, Nuno, I'm going to apply it.
Best Regards
--
Manuel Arostegui Ramirez #Linux Registered User 200896
next prev parent reply other threads:[~2004-06-14 14:59 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-12 9:59 new kernel bug Manuel Arostegui Ramirez
2004-06-12 12:33 ` Kalin KOZHUHAROV
2004-06-12 12:42 ` Manuel Arostegui Ramirez
2004-06-12 13:37 ` David Connolly
2004-06-12 15:08 ` Han Boetes
2004-06-12 15:08 ` Manuel Arostegui Ramirez
2004-06-14 13:58 ` Local DoS attack on i386 (was: new kernel bug) Gianni Tedesco
2004-06-14 14:05 ` Gianni Tedesco
2004-06-14 14:08 ` Manuel Arostegui Ramirez
2004-06-14 14:20 ` Nuno Monteiro
2004-06-14 14:59 ` Manuel Arostegui Ramirez [this message]
2004-06-15 4:34 ` Local DoS attack on i386 Andre Tomt
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