[PATCH v2] task_work: kasan: record task_work_add() call stack

[Jens Axboe]

On 3/15/21 8:44 PM, Walter Wu wrote:
> Why record task_work_add() call stack?
> Syzbot reports many use-after-free issues for task_work, see [1].
> After see the free stack and the current auxiliary stack, we think
> they are useless, we don't know where register the work, this work
> may be the free call stack, so that we miss the root cause and
> don't solve the use-after-free.
> 
> Add task_work_add() call stack into KASAN auxiliary stack in
> order to improve KASAN report. It is useful for programmers
> to solve use-after-free issues.

I think this is a very useful addition, especially as task_work
proliferates.

Reviewed-by: Jens Axboe <axboe at kernel.dk>

-- 
Jens Axboe