diff options
| author | Matt Johnston <matt@codeconstruct.com.au> | 2025-07-10 16:55:55 +0800 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-07-15 12:08:39 +0200 |
| commit | 3954502377ec05a1b37e2dc9bef0bacd4bbd71b2 (patch) | |
| tree | 24f468f62e7ae96c2f0c12e5c2e605cbac825a11 /net | |
| parent | net: mctp: mctp_test_route_extaddr_input cleanup (diff) | |
| download | linux-3954502377ec05a1b37e2dc9bef0bacd4bbd71b2.tar.gz linux-3954502377ec05a1b37e2dc9bef0bacd4bbd71b2.zip | |
net: mctp: Prevent duplicate binds
Disallow bind() calls that have the same arguments as existing bound
sockets. Previously multiple sockets could bind() to the same
type/local address, with an arbitrary socket receiving matched messages.
This is only a partial fix, a future commit will define precedence order
for MCTP_ADDR_ANY versus specific EID bind(), which are allowed to exist
together.
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://patch.msgid.link/20250710-mctp-bind-v4-2-8ec2f6460c56@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mctp/af_mctp.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c index aef74308c18e..0d073bc32ec1 100644 --- a/net/mctp/af_mctp.c +++ b/net/mctp/af_mctp.c @@ -73,7 +73,6 @@ static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen) lock_sock(sk); - /* TODO: allow rebind */ if (sk_hashed(sk)) { rc = -EADDRINUSE; goto out_release; @@ -611,15 +610,36 @@ static void mctp_sk_close(struct sock *sk, long timeout) static int mctp_sk_hash(struct sock *sk) { struct net *net = sock_net(sk); + struct sock *existing; + struct mctp_sock *msk; + int rc; + + msk = container_of(sk, struct mctp_sock, sk); /* Bind lookup runs under RCU, remain live during that. */ sock_set_flag(sk, SOCK_RCU_FREE); mutex_lock(&net->mctp.bind_lock); + + /* Prevent duplicate binds. */ + sk_for_each(existing, &net->mctp.binds) { + struct mctp_sock *mex = + container_of(existing, struct mctp_sock, sk); + + if (mex->bind_type == msk->bind_type && + mex->bind_addr == msk->bind_addr && + mex->bind_net == msk->bind_net) { + rc = -EADDRINUSE; + goto out; + } + } + sk_add_node_rcu(sk, &net->mctp.binds); - mutex_unlock(&net->mctp.bind_lock); + rc = 0; - return 0; +out: + mutex_unlock(&net->mctp.bind_lock); + return rc; } static void mctp_sk_unhash(struct sock *sk) |