net: mctp: Set SOCK_RCU_FREE

mkj · kuba-moo · commit 52024cd6ec71 · 2025-04-11T18:42:34.000-07:00
Bind lookup runs under RCU, so ensure that a socket doesn't go away in the middle of a lookup. Fixes: 833ef3b ("mctp: Populate socket implementation") Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Link: https://patch.msgid.link/20250410-mctp-rcu-sock-v1-1-872de9fdc877@codeconstruct.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
@@ -630,6 +630,9 @@ static int mctp_sk_hash(struct sock *sk)
 {
 	struct net *net = sock_net(sk);
 
+	/* Bind lookup runs under RCU, remain live during that. */
+	sock_set_flag(sk, SOCK_RCU_FREE);
+
 	mutex_lock(&net->mctp.bind_lock);
 	sk_add_node_rcu(sk, &net->mctp.binds);
 	mutex_unlock(&net->mctp.bind_lock);

Original file line number	Diff line number	Diff line change
`@@ -630,6 +630,9 @@ static int mctp_sk_hash(struct sock *sk)`
`630`	`630`	`{`
`631`	`631`	`struct net *net = sock_net(sk);`
`632`	`632`
	`633`	`+ /* Bind lookup runs under RCU, remain live during that. */`
	`634`	`+ sock_set_flag(sk, SOCK_RCU_FREE);`
	`635`	`+`
`633`	`636`	`mutex_lock(&net->mctp.bind_lock);`
`634`	`637`	`sk_add_node_rcu(sk, &net->mctp.binds);`
`635`	`638`	`mutex_unlock(&net->mctp.bind_lock);`