In the Linux kernel, the following vulnerability has been resolved: ovpn: fix NULL dereference when killing missing key ovpn_crypto_kill_key assumes both crypto slots are populated and dereferences each slot before checking it. That is not guaranteed: a peer can have only one installed key, and the kill path may be asked to remove a key that is not present. Read each slot once while holding the crypto state lock, check for NULL before looking at key_id, and only replace the slot that actually matches.
https://git.kernel.org/stable/c/acf32a5dff082044cf0fd9492f3c10b7357c15ee
https://git.kernel.org/stable/c/a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3
https://git.kernel.org/stable/c/41d44ac7a61e2f74453af40d4fe1b82af9ea0ada