diff --git a/include/net/sock.h b/include/net/sock.h index 05a1bbdf58054d..d08cfe190a78ba 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -577,6 +577,31 @@ static inline bool sk_user_data_is_nocopy(const struct sock *sk) #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) +/** + * __locked_read_sk_user_data_with_flags - return the pointer + * only if argument flags all has been set in sk_user_data. Otherwise + * return NULL + * + * @sk: socket + * @flags: flag bits + * + * The caller must be holding sk->sk_callback_lock. + */ +static inline void * +__locked_read_sk_user_data_with_flags(const struct sock *sk, + uintptr_t flags) +{ + uintptr_t sk_user_data = + (uintptr_t)rcu_dereference_check(__sk_user_data(sk), + lockdep_is_held(&sk->sk_callback_lock)); + + WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK); + + if ((sk_user_data & flags) == flags) + return (void *)(sk_user_data & SK_USER_DATA_PTRMASK); + return NULL; +} + /** * __rcu_dereference_sk_user_data_with_flags - return the pointer * only if argument flags all has been set in sk_user_data. Otherwise diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c index 85fa9dbfa8bf88..82c61612f382a6 100644 --- a/kernel/bpf/reuseport_array.c +++ b/kernel/bpf/reuseport_array.c @@ -24,7 +24,7 @@ void bpf_sk_reuseport_detach(struct sock *sk) struct sock __rcu **socks; write_lock_bh(&sk->sk_callback_lock); - socks = __rcu_dereference_sk_user_data_with_flags(sk, SK_USER_DATA_BPF); + socks = __locked_read_sk_user_data_with_flags(sk, SK_USER_DATA_BPF); if (socks) { WRITE_ONCE(sk->sk_user_data, NULL); /*