From: stian@nixia.no
To: "martin capitanio" <spam@capitanio.org>
Cc: stian@nixia.no, linux-kernel@vger.kernel.org
Subject: Re: timer + fpu stuff locks up computer
Date: Sat, 12 Jun 2004 18:15:30 +0200 (CEST) [thread overview]
Message-ID: <1855.83.109.11.80.1087056930.squirrel@nepa.nlc.no> (raw)
In-Reply-To: <200406121720.54123.spam@capitanio.org>
>> Does the other dirty nasty patch work for you?
> --- linux-2.6.6-rc3-mm1/kernel/signal.c 2004-06-09 18:36:12.000000000
> +0200
> +++ linux-2.6.6-rc3-mm1-fpuhotfix/kernel/signal.c 2004-06-12
> 18:10:31.573001808 +0200
> @@ -799,7 +799,15 @@
> can get more detailed information about the cause of
> the signal. */
> if (LEGACY_QUEUE(&t->pending, sig))
> + {
> + if (sig==8)
> + {
> + printk("Attempt to exploit known bug, process=%s pid=%p
> uid=%d\n",
> + t->comm, t->pid, t->uid);
> + do_exit(0);
> + }
> goto out;
> + }
>
> ret = send_signal(sig, info, t, &t->pending);
> if (!ret && !sigismember(&t->blocked, sig))
>
> 2.6.7-rc4-mm1-fpuhotfix:
> user$ ./evil
> ........................*...............................................
> ......................*
> Attempt to exploit known bug, process=evil pid=00000aa6 uid=1000
> note: evil[2726] exited with preempt_count 2
> bad: scheduling while atomic!
> [<c032a045>] schedule+0x4b5/0x4c0
> [<c01435cb>] zap_pmd_range+0x4b/0x70
> [<c014362d>] unmap_page_range+0x3d/0x70
> [<c014380b>] unmap_vmas+0x1ab/0x1c0
> [<c0147639>] exit_mmap+0x79/0x150
> [<c01184ee>] mmput+0x5e/0xa0
> [<c011c523>] do_exit+0x153/0x3e0
> [<c0122e6f>] specific_send_sig_info+0xff/0x100
> [<c0122eb2>] force_sig_info+0x42/0x90
> [<c0105be0>] do_coprocessor_error+0x0/0x20
> [<c0105b5e>] math_error+0xde/0x160
> [<c010b0f6>] restore_i387_fxsave+0x26/0xa0
> [<c0222c8c>] write_chan+0x18c/0x250
> [<c01170e0>] default_wake_function+0x0/0x10
> [<c01170e0>] default_wake_function+0x0/0x10
> [<c0104a05>] error_code+0x2d/0x38
> [<c010b0f6>] restore_i387_fxsave+0x26/0xa0
> [<c010b1fc>] restore_i387+0x8c/0x90
> [<c0103434>] restore_sigcontext+0x114/0x130
> [<c0103503>] sys_sigreturn+0xb3/0xd0
> [<c0103f6b>] syscall_call+0x7/0xb
>
> but it keeps the kernel alive :-)
The hotfix should probably me moved to arch/i386/traps.c before we start
to due atomic locks, sinse it is beond dirty to kill the process here when
we have locked down resources. But the best would be to fix the
problem-source, since this is just a workaround.
Stian Skjelstad
next prev parent reply other threads:[~2004-06-12 16:15 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-09 21:02 timer + fpu stuff locks my console race stian
2004-06-10 21:00 ` Matias Hermanrud Fjeld
2004-06-11 6:08 ` Lars Age Kamfjord
2004-06-12 2:53 ` Rik van Riel
2004-06-12 3:50 ` Rik van Riel
2004-06-12 13:44 ` Sergey Vlasov
2004-06-12 13:57 ` stian
2004-06-12 14:28 ` Sergey Vlasov
2004-06-12 14:25 ` timer + fpu stuff locks up computer Alexander Nyberg
2004-06-12 14:42 ` stian
2004-06-12 15:20 ` martin capitanio
2004-06-12 16:15 ` stian [this message]
2004-06-12 15:14 ` Sergey Vlasov
2004-06-12 18:45 ` Sergey Vlasov
2004-06-12 20:27 ` Alexander Nyberg
2004-06-12 4:35 ` timer + fpu stuff locks my console race Matt Mackall
[not found] <26h3z-t3-15@gated-at.bofh.it>
[not found] ` <26hGq-Zr-29@gated-at.bofh.it>
[not found] ` <26isF-1Im-11@gated-at.bofh.it>
[not found] ` <26lJU-4lC-23@gated-at.bofh.it>
2004-06-12 22:08 ` timer + fpu stuff locks up computer Andi Kleen
2004-06-13 13:06 ` Sergey Vlasov
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=1855.83.109.11.80.1087056930.squirrel@nepa.nlc.no \
--to=stian@nixia.no \
--cc=linux-kernel@vger.kernel.org \
--cc=spam@capitanio.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.