CVE-2024-50005

In the Linux kernel, the following vulnerability has been resolved:

mac802154: Fix potential RCU dereference issue in mac802154_scan_worker

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.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/540138377b22f601f06f55ebfa3ca171dcab471a
• https://git.kernel.org/stable/c/bff1709b3980bd7f80be6786f64cc9a9ee9e56da
• https://git.kernel.org/stable/c/d18f669461811dfe2915d5554ab2a9834f810013
• https://git.kernel.org/stable/c/e676e4ea76bbe7f1156d8c326b9b6753849481c2