Description:
Both 5.7 and 8.0 contain the following code in
TCP_socket::get_listener_socket() (omitting unrelated lines):
---
if (!getaddrinfo(ipv6_all_addresses, port_buf, &hints, &ai)) {
/*
IPv6 might be available (the system might be able to resolve an IPv6
address, but not be able to create an IPv6-socket). Try to create a
dummy IPv6-socket. Do not instrument that socket by P_S.
*/
...
}
if (ipv6_available) {
...
} else {
...
if (getaddrinfo(ipv4_all_addresses, port_buf, &hints, &ai)) {
...
}
}
---
After the first successful call to getaddrinfo(), ai contains a pointer
to a data structure allocated by the C library. That memory must be
freed with freeaddrinfo().
However, if ipv6_available == false (i.e. under circumstances described
in the comment), we do another call to getaddrinfo() overwriting the
previously returned pointer stored in ai without calling freeaddrinfo()
on it and thus, leaking allocated memory.
How to repeat:
Code analysis in
sql/conn_handler/socket_connection.cc:TCP_socket::get_listener_socket().
Description: Both 5.7 and 8.0 contain the following code in TCP_socket::get_listener_socket() (omitting unrelated lines): --- if (!getaddrinfo(ipv6_all_addresses, port_buf, &hints, &ai)) { /* IPv6 might be available (the system might be able to resolve an IPv6 address, but not be able to create an IPv6-socket). Try to create a dummy IPv6-socket. Do not instrument that socket by P_S. */ ... } if (ipv6_available) { ... } else { ... if (getaddrinfo(ipv4_all_addresses, port_buf, &hints, &ai)) { ... } } --- After the first successful call to getaddrinfo(), ai contains a pointer to a data structure allocated by the C library. That memory must be freed with freeaddrinfo(). However, if ipv6_available == false (i.e. under circumstances described in the comment), we do another call to getaddrinfo() overwriting the previously returned pointer stored in ai without calling freeaddrinfo() on it and thus, leaking allocated memory. How to repeat: Code analysis in sql/conn_handler/socket_connection.cc:TCP_socket::get_listener_socket().