diff --git a/include/net/sock.h b/include/net/sock.h index 66b56288c1d3..6c9a83016e95 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2098,7 +2098,7 @@ static inline int sk_rx_queue_get(const struct sock *sk) static inline void sk_set_socket(struct sock *sk, struct socket *sock) { - sk->sk_socket = sock; + WRITE_ONCE(sk->sk_socket, sock); if (sock) { WRITE_ONCE(sk->sk_uid, SOCK_INODE(sock)->i_uid); WRITE_ONCE(sk->sk_ino, SOCK_INODE(sock)->i_ino); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index dc47d3efc72e..0e217041958a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5590,15 +5590,28 @@ static void __skb_complete_tx_timestamp(struct sk_buff *skb, static bool skb_may_tx_timestamp(struct sock *sk, bool tsonly) { - bool ret; + struct socket *sock; + struct file *file; + bool ret = false; if (likely(tsonly || READ_ONCE(sock_net(sk)->core.sysctl_tstamp_allow_data))) return true; - read_lock_bh(&sk->sk_callback_lock); - ret = sk->sk_socket && sk->sk_socket->file && - file_ns_capable(sk->sk_socket->file, &init_user_ns, CAP_NET_RAW); - read_unlock_bh(&sk->sk_callback_lock); + /* The sk pointer remains valid as long as the skb is. The sk_socket and + * file pointer may become NULL if the socket is closed. Both structures + * (including file->cred) are RCU freed which means they can be accessed + * within a RCU read section. + */ + rcu_read_lock(); + sock = READ_ONCE(sk->sk_socket); + if (!sock) + goto out; + file = READ_ONCE(sock->file); + if (!file) + goto out; + ret = file_ns_capable(file, &init_user_ns, CAP_NET_RAW); +out: + rcu_read_unlock(); return ret; } diff --git a/net/socket.c b/net/socket.c index 136b98c54fb3..05952188127f 100644 --- a/net/socket.c +++ b/net/socket.c @@ -674,7 +674,7 @@ static void __sock_release(struct socket *sock, struct inode *inode) iput(SOCK_INODE(sock)); return; } - sock->file = NULL; + WRITE_ONCE(sock->file, NULL); } /**