In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix dfs-radar and temperature event locking The ath12k active pdevs are protected by RCU but the DFS-radar and temperature event handling code calling ath12k_mac_get_ar_by_pdev_id() was not marked as a read-side critical section. Mark the code in question as RCU read-side critical sections to avoid any potential use-after-free issues. Note that the temperature event handler looks like a place holder currently but would still trigger an RCU lockdep splat. Compile tested only.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.