--- /dev/null
+From eb40c63ac533eb4d4900ea47d59ceee71a36c5e9 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Wed, 25 Feb 2026 13:15:47 +0000
+Subject: net: annotate data-races around sk->sk_{data_ready,write_space}
+
+From: Eric Dumazet <edumazet@google.com>
+
+[ Upstream commit 2ef2b20cf4e04ac8a6ba68493f8780776ff84300 ]
+
+skmsg (and probably other layers) are changing these pointers
+while other cpus might read them concurrently.
+
+Add corresponding READ_ONCE()/WRITE_ONCE() annotations
+for UDP, TCP and AF_UNIX.
+
+Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
+Reported-by: syzbot+87f770387a9e5dc6b79b@syzkaller.appspotmail.com
+Closes: https://lore.kernel.org/netdev/699ee9fc.050a0220.1cd54b.0009.GAE@google.com/
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Cc: Daniel Borkmann <daniel@iogearbox.net>
+Cc: John Fastabend <john.fastabend@gmail.com>
+Cc: Jakub Sitnicki <jakub@cloudflare.com>
+Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
+Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
+Link: https://patch.msgid.link/20260225131547.1085509-1-edumazet@google.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ net/core/skmsg.c | 14 +++++++-------
+ net/ipv4/tcp.c | 4 ++--
+ net/ipv4/tcp_bpf.c | 2 +-
+ net/ipv4/tcp_input.c | 14 ++++++++------
+ net/ipv4/tcp_minisocks.c | 2 +-
+ net/ipv4/udp.c | 2 +-
+ net/ipv4/udp_bpf.c | 2 +-
+ net/unix/af_unix.c | 8 ++++----
+ 8 files changed, 25 insertions(+), 23 deletions(-)
+
+diff --git a/net/core/skmsg.c b/net/core/skmsg.c
+index 444b9b25ade28d..fd1a2464db0aab 100644
+--- a/net/core/skmsg.c
++++ b/net/core/skmsg.c
+@@ -1198,8 +1198,8 @@ void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
+ return;
+
+ psock->saved_data_ready = sk->sk_data_ready;
+- sk->sk_data_ready = sk_psock_strp_data_ready;
+- sk->sk_write_space = sk_psock_write_space;
++ WRITE_ONCE(sk->sk_data_ready, sk_psock_strp_data_ready);
++ WRITE_ONCE(sk->sk_write_space, sk_psock_write_space);
+ }
+
+ void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
+@@ -1209,8 +1209,8 @@ void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
+ if (!psock->saved_data_ready)
+ return;
+
+- sk->sk_data_ready = psock->saved_data_ready;
+- psock->saved_data_ready = NULL;
++ WRITE_ONCE(sk->sk_data_ready, psock->saved_data_ready);
++ WRITE_ONCE(psock->saved_data_ready, NULL);
+ strp_stop(&psock->strp);
+ }
+
+@@ -1283,8 +1283,8 @@ void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
+ return;
+
+ psock->saved_data_ready = sk->sk_data_ready;
+- sk->sk_data_ready = sk_psock_verdict_data_ready;
+- sk->sk_write_space = sk_psock_write_space;
++ WRITE_ONCE(sk->sk_data_ready, sk_psock_verdict_data_ready);
++ WRITE_ONCE(sk->sk_write_space, sk_psock_write_space);
+ }
+
+ void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock)
+@@ -1295,6 +1295,6 @@ void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock)
+ if (!psock->saved_data_ready)
+ return;
+
+- sk->sk_data_ready = psock->saved_data_ready;
++ WRITE_ONCE(sk->sk_data_ready, psock->saved_data_ready);
+ psock->saved_data_ready = NULL;
+ }
+diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
+index 076aa73c99fa81..82d6c01c7885c2 100644
+--- a/net/ipv4/tcp.c
++++ b/net/ipv4/tcp.c
+@@ -1479,7 +1479,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
+ err = sk_stream_error(sk, flags, err);
+ /* make sure we wake any epoll edge trigger waiter */
+ if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
+- sk->sk_write_space(sk);
++ READ_ONCE(sk->sk_write_space)(sk);
+ tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
+ }
+ return err;
+@@ -3844,7 +3844,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
+ break;
+ case TCP_NOTSENT_LOWAT:
+ WRITE_ONCE(tp->notsent_lowat, val);
+- sk->sk_write_space(sk);
++ READ_ONCE(sk->sk_write_space)(sk);
+ break;
+ case TCP_INQ:
+ if (val > 1 || val < 0)
+diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
+index 8e6c0737bfe128..9af7595bf8c452 100644
+--- a/net/ipv4/tcp_bpf.c
++++ b/net/ipv4/tcp_bpf.c
+@@ -750,7 +750,7 @@ int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
+ WRITE_ONCE(sk->sk_prot->unhash, psock->saved_unhash);
+ tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
+ } else {
+- sk->sk_write_space = psock->saved_write_space;
++ WRITE_ONCE(sk->sk_write_space, psock->saved_write_space);
+ /* Pairs with lockless read in sk_clone_lock() */
+ sock_replace_proto(sk, psock->sk_proto);
+ }
+diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
+index 645ff379c42544..91b019df7ddf79 100644
+--- a/net/ipv4/tcp_input.c
++++ b/net/ipv4/tcp_input.c
+@@ -4898,7 +4898,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
+
+ if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP);
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+ tcp_drop_reason(sk, skb, SKB_DROP_REASON_PROTO_MEM);
+ return;
+ }
+@@ -5104,7 +5104,7 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
+ void tcp_data_ready(struct sock *sk)
+ {
+ if (tcp_epollin_ready(sk, sk->sk_rcvlowat) || sock_flag(sk, SOCK_DONE))
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+ }
+
+ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
+@@ -5150,7 +5150,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
+ else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) {
+ reason = SKB_DROP_REASON_PROTO_MEM;
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP);
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+ goto drop;
+ }
+
+@@ -5570,7 +5570,9 @@ static void tcp_new_space(struct sock *sk)
+ tp->snd_cwnd_stamp = tcp_jiffies32;
+ }
+
+- INDIRECT_CALL_1(sk->sk_write_space, sk_stream_write_space, sk);
++ INDIRECT_CALL_1(READ_ONCE(sk->sk_write_space),
++ sk_stream_write_space,
++ sk);
+ }
+
+ /* Caller made space either from:
+@@ -5768,7 +5770,7 @@ static void tcp_urg(struct sock *sk, struct sk_buff *skb, const struct tcphdr *t
+ BUG();
+ WRITE_ONCE(tp->urg_data, TCP_URG_VALID | tmp);
+ if (!sock_flag(sk, SOCK_DEAD))
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+ }
+ }
+ }
+@@ -7133,7 +7135,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
+ sock_put(fastopen_sk);
+ goto drop_and_free;
+ }
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+ bh_unlock_sock(fastopen_sk);
+ sock_put(fastopen_sk);
+ } else {
+diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
+index 0b934b6ebb55b0..22b5748a6ee2c6 100644
+--- a/net/ipv4/tcp_minisocks.c
++++ b/net/ipv4/tcp_minisocks.c
+@@ -858,7 +858,7 @@ int tcp_child_process(struct sock *parent, struct sock *child,
+ ret = tcp_rcv_state_process(child, skb);
+ /* Wakeup parent, send SIGIO */
+ if (state == TCP_SYN_RECV && child->sk_state != state)
+- parent->sk_data_ready(parent);
++ READ_ONCE(parent->sk_data_ready)(parent);
+ } else {
+ /* Alas, it is possible again, because we do lookup
+ * in main socket hash table and lock on listening
+diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
+index a8bfab80d66a5f..d1714aaedf1768 100644
+--- a/net/ipv4/udp.c
++++ b/net/ipv4/udp.c
+@@ -1580,7 +1580,7 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
+ spin_unlock(&list->lock);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+- sk->sk_data_ready(sk);
++ READ_ONCE(sk->sk_data_ready)(sk);
+
+ busylock_release(busy);
+ return 0;
+diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
+index 0735d820e413f3..44271ba1adec15 100644
+--- a/net/ipv4/udp_bpf.c
++++ b/net/ipv4/udp_bpf.c
+@@ -143,7 +143,7 @@ int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
+ int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
+
+ if (restore) {
+- sk->sk_write_space = psock->saved_write_space;
++ WRITE_ONCE(sk->sk_write_space, psock->saved_write_space);
+ sock_replace_proto(sk, psock->sk_proto);
+ return 0;
+ }
+diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
+index a268a483efcd3f..f5b215ca76d249 100644
+--- a/net/unix/af_unix.c
++++ b/net/unix/af_unix.c
+@@ -1610,7 +1610,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+ __skb_queue_tail(&other->sk_receive_queue, skb);
+ spin_unlock(&other->sk_receive_queue.lock);
+ unix_state_unlock(other);
+- other->sk_data_ready(other);
++ READ_ONCE(other->sk_data_ready)(other);
+ sock_put(other);
+ return 0;
+
+@@ -2082,7 +2082,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
+ scm_stat_add(other, skb);
+ skb_queue_tail(&other->sk_receive_queue, skb);
+ unix_state_unlock(other);
+- other->sk_data_ready(other);
++ READ_ONCE(other->sk_data_ready)(other);
+ sock_put(other);
+ scm_destroy(&scm);
+ return len;
+@@ -2150,7 +2150,7 @@ static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other
+
+ sk_send_sigurg(other);
+ unix_state_unlock(other);
+- other->sk_data_ready(other);
++ READ_ONCE(other->sk_data_ready)(other);
+
+ return err;
+ }
+@@ -2243,7 +2243,7 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
+ scm_stat_add(other, skb);
+ skb_queue_tail(&other->sk_receive_queue, skb);
+ unix_state_unlock(other);
+- other->sk_data_ready(other);
++ READ_ONCE(other->sk_data_ready)(other);
+ sent += size;
+ }
+
+--
+2.53.0
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
