CVE-2026-64025

Summary

In the Linux kernel, the following vulnerability has been resolved:

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().

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/c9ea01768903ae47f210cd457af1dead6de7a9c3
• https://git.kernel.org/stable/c/7c8cf21bc4efb4af18d6096db3f8bd06d622251c
• https://git.kernel.org/stable/c/1861d369efd62d67796563bf3e01fc22e5626f8b
• https://git.kernel.org/stable/c/8a52139560f833c3975032e1f5762611e3a36d71
• https://git.kernel.org/stable/c/ddf8029623a1af20e984c040e89ff918158397ab

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