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

Miquel Raynal
2024-09-20T11:21:37Z

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.

>

Please delete this blank line as well.

And with that you can add my:

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>

> ---

Thanks,
Miquèl