diff options
| author | Matt Johnston <matt@codeconstruct.com.au> | 2025-07-10 16:55:55 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:30:31 +0200 |
| commit | 1b1a54308465ca1077021626af8d9615e6b21ffb (patch) | |
| tree | 28d40d09333b68d99074d51c339bf064b692b71c | |
| parent | 1da38b70d90f8529c060dd380d0c18e6d9595463 (diff) | |
net: mctp: Prevent duplicate binds
[ Upstream commit 3954502377ec05a1b37e2dc9bef0bacd4bbd71b2 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 57850d4dac5d..70aeebfc4182 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; @@ -629,15 +628,36 @@ 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) |