linux-kernel - Re: [stable 2.6.24] WARNING: at kernel/time/clockevents.c

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: <20080212230741.576b8004.akpm@linux-foundation.org>
Date:	Tue, 12 Feb 2008 23:07:41 -0800
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Frans Pop <elendil@...net.nl>
Cc:	linux-kernel@...r.kernel.org, john stultz <johnstul@...ibm.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [stable 2.6.24] WARNING: at kernel/time/clockevents.c

On Sun, 10 Feb 2008 14:40:21 +0100 Frans Pop <elendil@...net.nl> wrote:

> Kernel: vanilla 2.6.24 x86_64 SMP
> Environment: Debian unstable
> Processor: Intel(R) Pentium(R) D CPU 3.20GHz (dual core)
> 
> I've been running this kernel without problems since its release, but 
> yesterday evening I suddenly got the following error, and this afternoon it 
> was repeated (below). The system had been powered down in between.
> 
> I have no idea yet what triggers it and am unsure if I'll be able to 
> reproduce.
> 
> WARNING: at kernel/time/clockevents.c:82 clockevents_program_event()
> Pid: 2210, comm: ld-linux-x86-64 Not tainted 2.6.24 #1
> 
> Call Trace:
>  [<ffffffff8024af78>] ktime_get+0xc/0x41
>  [<ffffffff8024ea21>] clockevents_program_event+0x3b/0x94
>  [<ffffffff8024f890>] tick_program_event+0x31/0x4d
>  [<ffffffff8024a2c3>] hrtimer_reprogram+0x3b/0x51
>  [<ffffffff8024a43e>] enqueue_hrtimer+0x66/0x102
>  [<ffffffff8024ad01>] hrtimer_start+0x105/0x128
>  [<ffffffff803f8c9c>] rt_mutex_slowlock+0x90/0x53a
>  [<ffffffff80277a00>] find_extend_vma+0x16/0x59
>  [<ffffffff8025097a>] get_futex_key+0x82/0x14e
>  [<ffffffff80251a8d>] futex_lock_pi+0x60f/0x90d
>  [<ffffffff8024a6d3>] hrtimer_wakeup+0x0/0x21
>  [<ffffffff803f8c9c>] rt_mutex_slowlock+0x90/0x53a
>  [<ffffffff80252793>] do_futex+0xa08/0xa3d
>  [<ffffffff8022bd23>] __dequeue_entity+0x1c/0x32
>  [<ffffffff803f8261>] thread_return+0x3a/0xab
>  [<ffffffff802528a8>] sys_futex+0xe0/0xfe
>  [<ffffffff8020befe>] system_call+0x7e/0x83
> 

	if (unlikely(expires.tv64 < 0)) {
		WARN_ON_ONCE(1);
		return -ETIME;
	}

the hrtimer code is preparing an invalid ktime_t.  Note that
clockevents_program_event() actually fails when this happens - I am
surprised that this is not causing observeable userspace problems.

The WARN_ON_ONCE() means that you'll only see this warning once per boot. 
But the actually error could be happening any number of times without being
reported.

Looks pretty serious?
--
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/