inet_diag: annotate data-races in inet_diag_bc_sk()

inet_diag_bc_sk() runs with an unlocked socket,
annotate potential races with READ_ONCE().

Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: edumazet

net/ipv4/inet_diag.c

@@ -580,7 +580,7 @@ static void entry_fill_addrs(struct inet_diag_entry *entry,
 			     const struct sock *sk)
 {
 #if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6) {
+	if (entry->family == AF_INET6) {
 		entry->saddr = sk->sk_v6_rcv_saddr.s6_addr32;
 		entry->daddr = sk->sk_v6_daddr.s6_addr32;
 	} else
@@ -593,18 +593,18 @@ static void entry_fill_addrs(struct inet_diag_entry *entry,
 
 int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
 {
-	struct inet_sock *inet = inet_sk(sk);
+	const struct inet_sock *inet = inet_sk(sk);
 	struct inet_diag_entry entry;
 
 	if (!bc)
 		return 1;
 
-	entry.family = sk->sk_family;
+	entry.family = READ_ONCE(sk->sk_family);
 	entry_fill_addrs(&entry, sk);
-	entry.sport = inet->inet_num;
-	entry.dport = ntohs(inet->inet_dport);
-	entry.ifindex = sk->sk_bound_dev_if;
-	entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
+	entry.sport = READ_ONCE(inet->inet_num);
+	entry.dport = ntohs(READ_ONCE(inet->inet_dport));
+	entry.ifindex = READ_ONCE(sk->sk_bound_dev_if);
+	entry.userlocks = sk_fullsock(sk) ? READ_ONCE(sk->sk_userlocks) : 0;
 	if (sk_fullsock(sk))
 		entry.mark = READ_ONCE(sk->sk_mark);
 	else if (sk->sk_state == TCP_NEW_SYN_RECV)