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")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiawei Ye <jiawei.ye@xxxxxxxxxxx>
Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>