1 files changed, 16 insertions, 7 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 3c9e05332f17..8ec107748159 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -553,22 +553,27 @@ int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 		       int addr_len, int flags)
 {
 	struct sock *sk = sock->sk;
+	const struct proto *prot;
 	int err;
 
 	if (addr_len < sizeof(uaddr->sa_family))
 		return -EINVAL;
+
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	prot = READ_ONCE(sk->sk_prot);
+
 	if (uaddr->sa_family == AF_UNSPEC)
-		return sk->sk_prot->disconnect(sk, flags);
+		return prot->disconnect(sk, flags);
 
 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
-		err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
+		err = prot->pre_connect(sk, uaddr, addr_len);
 		if (err)
 			return err;
 	}
 
 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 		return -EAGAIN;
-	return sk->sk_prot->connect(sk, uaddr, addr_len);
+	return prot->connect(sk, uaddr, addr_len);
 }
 EXPORT_SYMBOL(inet_dgram_connect);
 
@@ -731,10 +736,11 @@ EXPORT_SYMBOL(inet_stream_connect);
 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 		bool kern)
 {
-	struct sock *sk1 = sock->sk;
+	struct sock *sk1 = sock->sk, *sk2;
 	int err = -EINVAL;
-	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
 
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
 	if (!sk2)
 		goto do_err;
 
@@ -809,6 +815,7 @@ ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 		      size_t size, int flags)
 {
 	struct sock *sk = sock->sk;
+	const struct proto *prot;
 
 	sock_rps_record_flow(sk);
 
@@ -817,8 +824,10 @@ ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 	    inet_autobind(sk))
 		return -EAGAIN;
 
-	if (sk->sk_prot->sendpage)
-		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	prot = READ_ONCE(sk->sk_prot);
+	if (prot->sendpage)
+		return prot->sendpage(sk, page, offset, size, flags);
 	return sock_no_sendpage(sock, page, offset, size, flags);
 }
 EXPORT_SYMBOL(inet_sendpage);