Re: [PATCH] xacct_add_tsk: fix pure theoretical ->mm use-after-free

From: Jay Lan
Date: Mon Oct 30 2006 - 22:09:00 EST


Oleg Nesterov wrote:
> On 10/30, Jay Lan wrote:
>> Oleg Nesterov wrote:
>>> Paranoid fix. The task can free its ->mm after the 'if (p->mm)' check.
>> Why this change is necessary? This routine is indirectly invoked by
>> taskstats_exit_send() routine called inside do_exit():
>
> Not only, please note
>
> taskstats_user_cmd(TASKSTATS_CMD_ATTR_PID)->fill_pid()->xacct_add_tsk()
>
> path. This tsk is not 'current', it was found by find_task_by_pid(), and
> it may exit at any time.

OK. Thanks!

Acked-by: Jay Lan <jlan@xxxxxxx>

>
> Oleg.
>

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