In the Linux kernel, the following vulnerability has been resolved:net: Fix TOCTOU issue in sk_is_readable()sk->sk_prot->sock_is_readable is a valid function pointer when sk residesin a sockmap. After the last sk_psock_put() (which usually happens whensocket is removed from sockmap), sk->sk_prot gets restored andsk->sk_prot->sock_is_readable becomes NULL.This makes sk_is_readable() racy, if the value of sk->sk_prot is reloadedafter the initial check. Which in turn may lead to a null pointerdereference.Ensure the function pointer does not turn NULL after the check.
No PoCs from references.
- https://github.com/w4zu/Debian_security