diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2023-04-20 19:17:13 +0200 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2023-05-18 13:11:09 -0400 |
| commit | e3d9387f002612093dbeaa272f7930ce5108033f (patch) | |
| tree | 17040b845b29070d3bfadcf0525f503d03d8c126 /net/mptcp/subflow.c | |
| parent | c52df19e3759055cf07d1c0030c46ea958163aa9 (diff) | |
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 owning user-space process, via the MPTCP
socket owning the subflow.
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>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'net/mptcp/subflow.c')
| -rw-r--r-- | net/mptcp/subflow.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index ba065b66551a..76952cf74fc0 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1694,6 +1694,10 @@ int mptcp_subflow_create_socket(struct sock *sk, unsigned short family, lock_sock_nested(sf->sk, SINGLE_DEPTH_NESTING); + err = security_mptcp_add_subflow(sk, sf->sk); + if (err) + goto release_ssk; + /* the newly created socket has to be in the same cgroup as its parent */ mptcp_attach_cgroup(sk, sf->sk); @@ -1706,6 +1710,8 @@ int mptcp_subflow_create_socket(struct sock *sk, unsigned short family, get_net_track(net, &sf->sk->ns_tracker, GFP_KERNEL); sock_inuse_add(net, 1); err = tcp_set_ulp(sf->sk, "mptcp"); + +release_ssk: release_sock(sf->sk); if (err) { |