In the Linux kernel, the following vulnerability has been resolved: netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets When calling netlblconnsetattr(), addr->safamily is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipsosocksetattr() is triggered. Inside this function, the following code is executed: skfullsock(sk) ? inetsk(sk)->pinet6 : NULL; Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference. This patch fixes the issue by checking if inet6sk(sk) returns a NULL pointer before accessing pinet6.