Bug 2502375 (CVE-2026-64025) - CVE-2026-64025 kernel: bpf, skmsg: fix verdict sk_data_ready racing with ktls rx
Summary: CVE-2026-64025 kernel: bpf, skmsg: fix verdict sk_data_ready racing with ktls rx
Keywords:
Status: NEW
Alias: CVE-2026-64025
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-19 16:04 UTC by OSIDB Bzimport
Modified: 2026-09-07 10:10 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-07-19 16:04:41 UTC
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().


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