linux-kernel - Re: 2.6.35-rc3-git4 - kernel/sched.c:616 invoked rcu_dereference

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: <AANLkTikGJCbX8Rp9ghh63oMc5p9raQtpg7ZWc7pJ8yFq@mail.gmail.com>
Date:	Thu, 5 Aug 2010 13:31:10 -0400
From:	Ilia Mirkin <imirkin@...m.mit.edu>
To:	paulmck@...ux.vnet.ibm.com
Cc:	Miles Lane <miles.lane@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Dave Jones <davej@...hat.com>,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	Ingo Molnar <mingo@...e.hu>, a.p.zijlstra@...llo.nl
Subject: Re: 2.6.35-rc3-git4 - kernel/sched.c:616 invoked rcu_dereference_check() 
	without protection!

On Thu, Jul 1, 2010 at 6:18 PM, Paul E. McKenney
<paulmck@...ux.vnet.ibm.com> wrote:
> On Thu, Jul 01, 2010 at 08:21:43AM -0400, Miles Lane wrote:
>> [ INFO: suspicious rcu_dereference_check() usage. ]
>> ---------------------------------------------------
>> kernel/sched.c:616 invoked rcu_dereference_check() without protection!
>>
>> other info that might help us debug this:
>>
>> rcu_scheduler_active = 1, debug_locks = 1
>> 3 locks held by swapper/1:
>>   #0:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff81042914>]
>> cpu_maps_update_begin+0x12/0x14
>>   #1:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8104294f>]
>> cpu_hotplug_begin+0x27/0x4e
>>   #2:  (&rq->lock){-.-...}, at: [<ffffffff812f8502>] init_idle+0x2b/0x114
>
> Hello, Miles!
>
> I believe that this one is fixed by commit dc61b1d6 in -tip.

Hi Paul,

Looks like that commit made it into 2.6.35:

git tag -l --contains dc61b1d65e353d638b2445f71fb8e5b5630f2415 v2.6.35*
v2.6.35
v2.6.35-rc4
v2.6.35-rc5
v2.6.35-rc6

However I still get:

[    0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03
[    0.052999] lockdep: fixing up alternatives.
[    0.054105]
[    0.054106] ===================================================
[    0.054999] [ INFO: suspicious rcu_dereference_check() usage. ]
[    0.054999] ---------------------------------------------------
[    0.054999] kernel/sched.c:616 invoked rcu_dereference_check()
without protection
!
[    0.054999]
[    0.054999] other info that might help us debug this:
[    0.054999]
[    0.054999]
[    0.054999] rcu_scheduler_active = 1, debug_locks = 1
[    0.054999] 3 locks held by swapper/1:
[    0.054999]  #0:  (cpu_add_remove_lock){+.+.+.}, at:
[<ffffffff814be933>] cpu_up+
0x42/0x6a
[    0.054999]  #1:  (cpu_hotplug.lock){+.+.+.}, at:
[<ffffffff810400d8>] cpu_hotplu
g_begin+0x2a/0x51
[    0.054999]  #2:  (&rq->lock){-.-...}, at: [<ffffffff814be2f7>]
init_idle+0x2f/0x
113
[    0.054999]
[    0.054999] stack backtrace:
[    0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1
[    0.054999] Call Trace:
[    0.054999]  [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3
[    0.054999]  [<ffffffff810325c3>] task_group+0x7b/0x8a
[    0.054999]  [<ffffffff810325e5>] set_task_rq+0x13/0x40
[    0.054999]  [<ffffffff814be39a>] init_idle+0xd2/0x113
[    0.054999]  [<ffffffff814be78a>] fork_idle+0xb8/0xc7
[    0.054999]  [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b
[    0.054999]  [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b
[    0.054999]  [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724
[    0.054999]  [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b
[    0.054999]  [<ffffffff814be876>] _cpu_up+0xac/0x127
[    0.054999]  [<ffffffff814be946>] cpu_up+0x55/0x6a
[    0.054999]  [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff
[    0.054999]  [<ffffffff81003854>] kernel_thread_helper+0x4/0x10
[    0.054999]  [<ffffffff814c353c>] ? restore_args+0x0/0x30
[    0.054999]  [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff
[    0.054999]  [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10
[    0.056074] Booting Node   0, Processors  #1lockdep: fixing up alternatives.
[    0.130045]  #2lockdep: fixing up alternatives.
[    0.203089]  #3 Ok.
[    0.275286] Brought up 4 CPUs
[    0.276005] Total of 4 processors activated (16017.17 BogoMIPS).

-- 
Ilia Mirkin
imirkin@...m.mit.edu
--
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/