Re: [PATCH -next v2] blk-throttle: Set BIO_THROTTLED when bio has been throttled

[QiuLaibin]

friendly ping....

在 2022/3/2 21:51, Ming Lei 写道:
> On Tue, Mar 01, 2022 at 08:39:19PM +0800, Laibin Qiu wrote:
> > 1.In current process, all bio will set the BIO_THROTTLED flag
> > after __blk_throtl_bio().
> >
> > 2.If bio needs to be throttled, it will start the timer and
> > stop submit bio directly. Bio will submit in
> > blk_throtl_dispatch_work_fn() when the timer expires.But in
> > the current process, if bio is throttled. The BIO_THROTTLED
> > will be set to bio after timer start. If the bio has been
> > completed, it may cause use-after-free blow.
> >
> > BUG: KASAN: use-after-free in blk_throtl_bio+0x12f0/0x2c70
> > Read of size 2 at addr ffff88801b8902d4 by task fio/26380
>
> After the queue lock is released, the bio can be dispatched & completed,
> so it shouldn't be touched after lock release:
>
> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
>
> Thanks,
> Ming
>
> .