security, lsm: Introduce security_mptcp_add_subflow()
MPTCP can create subflows in kernel context, and later indirectly
expose them to user-space, via the owning mptcp socket.
As discussed in the reported link, the above causes unexpected failures
for server, MPTCP-enabled applications.
Let's introduce a new LSM hook to allow the security module to relabel
the subflow according to the owing process.
Note that the new hook requires both the mptcp socket and the new
subflow. This could allow future extensions, e.g. explicitly validating
the mptcp <-> subflow linkage.
Link: https://lore.kernel.org/mptcp/CAHC9VhTNh-YwiyTds=P1e3rixEDqbRTFj22bpya=+qJqfcaMfg@mail.gmail.com/
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
4 files changed
