Re: [PATCH v2] mac802154: Fix potential RCU dereference issue in mac802154_scan_worker

Jiawei Ye
2024-09-21T05:34:11Z

Hi Miquèl,

I'm sorry for the accidental email sent while testing my email setup. Please disregard the previous message.

On 9/20/24 19:21, Miquel Raynal wrote:
> Hi Jiawei,
>
> jiawei.ye@foxmail.com wrote on Fri, 20 Sep 2024 04:03:32 +0000:
>
> > In the `mac802154_scan_worker` function, the `scan_req->type` field was
> > accessed after the RCU read-side critical section was unlocked. According
> > to RCU usage rules, this is illegal and can lead to unpredictable
> > behavior, such as accessing memory that has been updated or causing
> > use-after-free issues.
> >
> > This possible bug was identified using a static analysis tool developed
> > by myself, specifically designed to detect RCU-related issues.
> >
> > To address this, the `scan_req->type` value is now stored in a local
> > variable `scan_req_type` while still within the RCU read-side critical
> > section. The `scan_req_type` is then used after the RCU lock is released,
> > ensuring that the type value is safely accessed without violating RCU
> > rules.
> >
> > Fixes: e2c3e6f53a7a ("mac802154: Handle active scanning")
> > Signed-off-by: Jiawei Ye <jiawei.ye@foxmail.com>
>
> I think net maintainers now expect the Cc: stable tag to be put here
> when there is a reason to backport, which I believe is the case here.
> So please add this line here.
>

Does this mean I should use Cc: stable@vger.kernel.org? I am not familiar with this procedure.

> >
>
> Please delete this blank line as well.
>
> And with that you can add my:
>
> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
>
> > ---
>
> Thanks,
> Miquèl

Do I need to resend patch v2 with the "Resend" label?

Thank you for your assistance.

Best regards,
Jiawei Ye