Commit 78e2baf3 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: add TIME_WAIT logic to sk_to_full_sk() 



TCP will soon attach TIME_WAIT sockets to some ACK and RST.

Make sure sk_to_full_sk() detects this and does not return
a non full socket.

v3: also changed sk_const_to_full_sk()

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: default avatarBrian Vazquez <brianvv@google.com>
Link: https://patch.msgid.link/20241010174817.1543642-2-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 76d37e4f

include/linux/bpf-cgroup.h

+1 −1
Original line number Diff line number Diff line
@@ -209,7 +209,7 @@ static inline bool cgroup_bpf_sock_enabled(struct sock *sk, 
	int __ret = 0;							       \

	if (cgroup_bpf_enabled(CGROUP_INET_EGRESS) && sk) {		       \

		typeof(sk) __sk = sk_to_full_sk(sk);			       \

		if (sk_fullsock(__sk) && __sk == skb_to_full_sk(skb) &&	       \

		if (__sk && __sk == skb_to_full_sk(skb) &&	       \

		    cgroup_bpf_sock_enabled(__sk, CGROUP_INET_EGRESS))	       \

			__ret = __cgroup_bpf_run_filter_skb(__sk, skb,	       \

						      CGROUP_INET_EGRESS); \

include/net/inet_sock.h

+6 −2
Original line number Diff line number Diff line
@@ -321,8 +321,10 @@ static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet) 
static inline struct sock *sk_to_full_sk(struct sock *sk)

{

#ifdef CONFIG_INET

	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)

	if (sk && READ_ONCE(sk->sk_state) == TCP_NEW_SYN_RECV)

		sk = inet_reqsk(sk)->rsk_listener;

	if (sk && READ_ONCE(sk->sk_state) == TCP_TIME_WAIT)

		sk = NULL;

#endif

	return sk;

}
@@ -331,8 +333,10 @@ static inline struct sock *sk_to_full_sk(struct sock *sk) 
static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)

{

#ifdef CONFIG_INET

	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)

	if (sk && READ_ONCE(sk->sk_state) == TCP_NEW_SYN_RECV)

		sk = ((const struct request_sock *)sk)->rsk_listener;

	if (sk && READ_ONCE(sk->sk_state) == TCP_TIME_WAIT)

		sk = NULL;

#endif

	return sk;

}

net/core/filter.c

+1 −5
Original line number Diff line number Diff line
@@ -6778,8 +6778,6 @@ __bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, 
		/* sk_to_full_sk() may return (sk)->rsk_listener, so make sure the original sk

		 * sock refcnt is decremented to prevent a request_sock leak.

		 */

		if (!sk_fullsock(sk2))

			sk2 = NULL;

		if (sk2 != sk) {

			sock_gen_put(sk);

			/* Ensure there is no need to bump sk2 refcnt */
@@ -6826,8 +6824,6 @@ bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, 
		/* sk_to_full_sk() may return (sk)->rsk_listener, so make sure the original sk

		 * sock refcnt is decremented to prevent a request_sock leak.

		 */

		if (!sk_fullsock(sk2))

			sk2 = NULL;

		if (sk2 != sk) {

			sock_gen_put(sk);

			/* Ensure there is no need to bump sk2 refcnt */
@@ -7276,7 +7272,7 @@ BPF_CALL_1(bpf_get_listener_sock, struct sock *, sk) 
{

	sk = sk_to_full_sk(sk);



	if (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_RCU_FREE))

	if (sk && sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_RCU_FREE))

		return (unsigned long)sk;



	return (unsigned long)NULL;