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EPSS 0.2%top 94%

In the Linux kernel, the following vulnerability has been resolved: bpf, skmsg: fix verdict sk_data_ready racing with ktls rx… (CVE-2026-64025)

0
Critical
Published: 07/19/2026 (07/19/2026, 18:31:49 UTC)
Source: GCVE Database

Description

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().

CVSS v3.1

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 07/19/2026, 19:54:25 UTC

Technical Analysis

The vulnerability (CVE-2026-64025) in the Linux kernel concerns the bpf, skmsg subsystem where sk_psock_verdict_data_ready() lacked a guard present in sk_psock_strp_data_ready() to defer to the TLS RX context's saved_data_ready callback. This omission caused a race condition when a socket was inserted into a sockmap before TLS RX was configured. On data arrival, the sk_receive_queue was drained without advancing the copied sequence number, leading to stale TCP queue state and a use-after-free when tls_decrypt_sg() accessed a freed skb fragment list. The patch applies the same guard as in sk_psock_strp_data_ready(), ensuring TLS retains sole ownership of the receive queue and preventing the use-after-free.

Potential Impact

This vulnerability can cause a use-after-free condition in the Linux kernel's networking stack during TLS receive processing with BPF socket verdict programs. Such a flaw may lead to kernel warnings, potential crashes, or memory corruption. No known exploits in the wild have been reported. The impact is limited to kernel stability and security related to TLS data handling and BPF socket verdict programs.

Mitigation Recommendations

A fix has been applied to the Linux kernel source code to address this issue by adding the necessary guard in sk_psock_verdict_data_ready(). Users should update their Linux kernel to a version that includes this patch. Since this is not a cloud service, remediation requires applying the official kernel update. Patch status is not explicitly confirmed in the provided data; users should consult the vendor or kernel mailing list advisories for the exact fixed versions and update accordingly.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
GHSA-r22g-q228-2mx8
Osv Schema Version
1.4.0
Aliases
["CVE-2026-64025"]
Ecosystems
[]
Database Specific Severity
null
Cvss Version
null

Threat ID: 6a5d27a92a4a8d598912c892

Added to database: 07/19/2026, 19:38:17 UTC

Last enriched: 07/19/2026, 19:54:25 UTC

Last updated: 07/20/2026, 19:56:56 UTC

Views: 12

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