Re: [PATCH] idr: prevent NULL deref on lookups before insertions

From: Sasha Levin
Date: Wed Feb 20 2013 - 14:24:23 EST


On 02/20/2013 01:45 PM, Tejun Heo wrote:
> Hello, Sasha.
>
> On Wed, Feb 20, 2013 at 10:44 AM, Sasha Levin <sasha.levin@xxxxxxxxxx> wrote:
>> 'hint' will be NULL if we're looking up before adding anything
>> to the IDR.
>>
>> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
>
> Andy Shevchenko already posted fix (and free_layer() needs an update too).

Sorry about that, didn't see one on lkml so I've sent mine.

What about a patch that deals with:

[ 67.992946] ------------[ cut here ]------------
[ 67.994133] WARNING: at lib/idr.c:669 idr_find_slowpath+0x36/0x170()
[ 67.999650] Modules linked in:
[ 68.000469] Pid: 7156, comm: trinity Tainted: G W 3.8.0-next-20130220-sasha-00006-g3d6f01c-dirty #6
[ 68.005136] Call Trace:
[ 68.005719] [<ffffffff8110c96b>] warn_slowpath_common+0x8b/0xc0
[ 68.011168] [<ffffffff8110c9b5>] warn_slowpath_null+0x15/0x20
[ 68.012488] [<ffffffff81a23506>] idr_find_slowpath+0x36/0x170
[ 68.013805] [<ffffffff8113bbcf>] __lock_timer+0x12f/0x240
[ 68.015686] [<ffffffff8113baa0>] ? posix_timer_fn+0xd0/0xd0
[ 68.016946] [<ffffffff8113c64c>] sys_timer_delete+0x2c/0x180
[ 68.018478] [<ffffffff83dab0f5>] ? tracesys+0x7e/0xe6
[ 68.019647] [<ffffffff83dab158>] tracesys+0xe1/0xe6
[ 68.020941] ---[ end trace 6d02b1896fa2505b ]---


Thanks,
Sasha
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