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 resides in a sockmap. After the last sk_psock_put() (which usually happens when socket is removed from sockmap), sk->sk_prot gets restored and sk->sk_prot->sock_is_readable becomes NULL. This makes sk_is_readable() racy, if the value of sk->sk_prot is reloaded after the initial check. Which in turn may lead to a null pointer dereference. Ensure the function pointer does not turn NULL after the check.
| Product | Vendor | Version |
|---|---|---|
| Linux | Linux | n/a |
| Linux | Linux | n/a |
| Linux | Linux | x64-based Systems Service Pack 1 |
| Linux | Linux | Windows RT 8.1 |