diff options
| author | Xingwang Xiang <v3rdant.xiang@gmail.com> | 2026-05-17 23:56:26 +0900 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-20 17:21:21 -0700 |
| commit | ddf8029623a1af20e984c040e89ff918158397ab (patch) | |
| tree | 4152df891a8f66d00a97d541e06c77592e8d63b3 | |
| parent | e7c70bf97e90d974cd575e4c90f8f9b07d056da3 (diff) | |
bpf, skmsg: fix verdict sk_data_ready racing with ktls rx
sk_psock_strp_data_ready() already checks tls_sw_has_ctx_rx() and
defers to psock->saved_data_ready when a TLS RX context is present,
avoiding a conflict with the TLS strparser's ownership of the receive
queue (commit e91de6afa81c, "bpf: Fix running sk_skb program types
with ktls").
sk_psock_verdict_data_ready() has no equivalent guard. When a socket
is inserted into a sockmap (BPF_SK_SKB_VERDICT) before TLS RX is
configured, tls_sw_strparser_arm() saves sk_psock_verdict_data_ready
as rx_ctx->saved_data_ready. On data arrival:
tls_data_ready -> tls_strp_data_ready -> tls_rx_msg_ready
-> saved_data_ready() = sk_psock_verdict_data_ready()
-> tcp_read_skb() drains sk_receive_queue via __skb_unlink()
without calling tcp_eat_skb(), so copied_seq is not advanced.
tls_strp_msg_load() then finds tcp_inq() >= full_len (stale), calls
tcp_recv_skb() on the now-empty queue, hits WARN_ON_ONCE(!first), and
returns with rx_ctx->strp.anchor.frag_list pointing at a psock-owned
(potentially freed) skb. tls_decrypt_sg() subsequently walks that
frag_list: use-after-free.
Apply the same fix as sk_psock_strp_data_ready(): if a TLS RX context
is present, call psock->saved_data_ready (sock_def_readable) to wake
recv() waiters and return immediately, leaving the receive queue
untouched. TLS retains sole ownership of the queue and decrypts the
record normally through tls_sw_recvmsg().
Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program")
Signed-off-by: Xingwang Xiang <v3rdant.xiang@gmail.com>
Link: https://patch.msgid.link/20260517145630.20521-2-v3rdant.xiang@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/core/skmsg.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 6187a83bd741..e1850caf1a71 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -1268,12 +1268,19 @@ out: static void sk_psock_verdict_data_ready(struct sock *sk) { const struct proto_ops *ops = NULL; + struct sk_psock *psock; struct socket *sock; int copied; trace_sk_data_ready(sk); rcu_read_lock(); + psock = sk_psock(sk); + if (psock && tls_sw_has_ctx_rx(sk)) { + psock->saved_data_ready(sk); + rcu_read_unlock(); + return; + } sock = READ_ONCE(sk->sk_socket); if (likely(sock)) ops = READ_ONCE(sock->ops); @@ -1283,8 +1290,6 @@ static void sk_psock_verdict_data_ready(struct sock *sk) copied = ops->read_skb(sk, sk_psock_verdict_recv); if (copied >= 0) { - struct sk_psock *psock; - rcu_read_lock(); psock = sk_psock(sk); if (psock) |