selinux: check connect-related permissions on TCP Fast Open

selinux: check connect-related permissions on TCP Fast Open

Similar to Landlock, SELinux was not updated when TCP Fast Open
support was introduced to ensure connect-related permissions are
checked when using TCP Fast Open. Update its socket_sendmsg() hook to
call selinux_socket_connect() when MSG_FASTOPEN is passed.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-security-module/20260616201615.275032-1-hexlabsecurity@proton.me/
Link: https://lore.kernel.org/linux-security-module/20260617180526.15627-2-matthieu@buffet.re/
Reported-by: Bryam Vargas <hexlabsecurity@proton.me>
Reported-by: Matthieu Buffet <matthieu@buffet.re>
Reported-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Bryam Vargas <hexlabsecurity@proton.me>
Signed-off-by: Paul Moore <paul@paul-moore.com>