diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 8fe7900f1949..7d7b7523d126 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -441,11 +441,14 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sock *sk = sock->sk; u32 flags = BIND_WITH_LOCK; + const struct proto *prot; int err = 0; + /* IPV6_ADDRFORM can change sk->sk_prot under us. */ + prot = READ_ONCE(sk->sk_prot); /* If the socket has its own bind function then use it. */ - if (sk->sk_prot->bind) - return sk->sk_prot->bind(sk, uaddr, addr_len); + if (prot->bind) + return prot->bind(sk, uaddr, addr_len); if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; @@ -555,6 +558,7 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) void __user *argp = (void __user *)arg; struct sock *sk = sock->sk; struct net *net = sock_net(sk); + const struct proto *prot; switch (cmd) { case SIOCADDRT: @@ -572,9 +576,11 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) case SIOCSIFDSTADDR: return addrconf_set_dstaddr(net, argp); default: - if (!sk->sk_prot->ioctl) + /* IPV6_ADDRFORM can change sk->sk_prot under us. */ + prot = READ_ONCE(sk->sk_prot); + if (!prot->ioctl) return -ENOIOCTLCMD; - return sk->sk_prot->ioctl(sk, cmd, arg); + return prot->ioctl(sk, cmd, arg); } /*NOTREACHED*/ return 0; @@ -636,11 +642,14 @@ INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *, int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) { struct sock *sk = sock->sk; + const struct proto *prot; if (unlikely(inet_send_prepare(sk))) return -EAGAIN; - return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg, + /* IPV6_ADDRFORM can change sk->sk_prot under us. */ + prot = READ_ONCE(sk->sk_prot); + return INDIRECT_CALL_2(prot->sendmsg, tcp_sendmsg, udpv6_sendmsg, sk, msg, size); } @@ -650,13 +659,16 @@ int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int flags) { struct sock *sk = sock->sk; + const struct proto *prot; int addr_len = 0; int err; if (likely(!(flags & MSG_ERRQUEUE))) sock_rps_record_flow(sk); - err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg, + /* IPV6_ADDRFORM can change sk->sk_prot under us. */ + prot = READ_ONCE(sk->sk_prot); + err = INDIRECT_CALL_2(prot->recvmsg, tcp_recvmsg, udpv6_recvmsg, sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); if (err >= 0) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index a733803a710c..222f6bf220ba 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -475,7 +475,8 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sock_prot_inuse_add(net, sk->sk_prot, -1); sock_prot_inuse_add(net, &tcp_prot, 1); - sk->sk_prot = &tcp_prot; + /* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */ + WRITE_ONCE(sk->sk_prot, &tcp_prot); icsk->icsk_af_ops = &ipv4_specific; sk->sk_socket->ops = &inet_stream_ops; sk->sk_family = PF_INET; @@ -489,7 +490,8 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sock_prot_inuse_add(net, sk->sk_prot, -1); sock_prot_inuse_add(net, prot, 1); - sk->sk_prot = prot; + /* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */ + WRITE_ONCE(sk->sk_prot, prot); sk->sk_socket->ops = &inet_dgram_ops; sk->sk_family = PF_INET; }