In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: Fix UAF on sco_sock_timeout conn->sk maybe have been unlinked/freed while waiting for sco_conn_lock so this checks if the conn->sk is still valid by checking if it part of sco_sk_list.
https://git.kernel.org/stable/c/d30803f6a972b5b9e26d1d43b583c7ec151de04b
https://git.kernel.org/stable/c/9ddda5d967e84796e7df1b54a55f36b4b9f21079
https://git.kernel.org/stable/c/80b05fbfa998480fb3d5299d93eab946f51e9c36
https://git.kernel.org/stable/c/1bf4470a3939c678fb822073e9ea77a0560bc6bb