CVE-2026-72221
Received Received - Intake

BaseFortify

Publication date: 2026-08-15

Last updated on: 2026-08-15

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: sunrpc: wait for in-flight TLS handshake callback when cancel loses race When wait_for_completion_interruptible_timeout() in svc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and tls_handshake_cancel() then returns false, handshake_complete() has won the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and is about to invoke svc_tcp_handshake_done(), but the callback's side effects on xpt_flags and on svsk->sk_handshake_done have not yet committed. The current code reads xpt_flags immediately to decide whether the session succeeded. Two races result. If the callback has executed set_bit(XPT_TLS_SESSION) but not yet clear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session, enqueues the transport, and returns. svc_xprt_received() then clears XPT_BUSY, a worker thread picks the transport up, the dispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set, and xpo_handshake is invoked a second time. That svc_tcp_handshake() calls init_completion(&svsk->sk_handshake_done) while the original callback concurrently calls complete_all() on it, corrupting the embedded swait_queue. If the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet entered svc_tcp_handshake_done(), svc_tcp_handshake() reads XPT_TLS_SESSION as clear and tears the connection down even though the handshake is about to succeed. Wait for the callback to commit before inspecting xpt_flags. The completion is guaranteed to fire because handshake_complete() invokes svc_tcp_handshake_done() unconditionally once it has set HANDSHAKE_F_REQ_COMPLETED.

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Meta Information

Published
2026-08-15
Last Modified
2026-08-15
Generated
2026-08-15
AI Q&A
2026-08-15
EPSS Evaluated
N/A
NVD
CVE-2026-72221
EUVD
EUVD-2026-59120

Affected Vendors & Products

Currently, no data is known.

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a race condition in the sunrpc module during TLS handshake cancellation. When a timeout or signal interrupts the handshake process, the system may incorrectly assume the session failed even though it is about to succeed. This happens because the code checks session status before the handshake completion callback fully commits its changes, leading to potential corruption or improper connection handling.

Impact Analysis

This vulnerability could cause unreliable RPC over TLS connections, leading to failed or corrupted network sessions. In severe cases, it might result in data loss or service disruptions for applications relying on secure remote procedure calls, particularly in distributed systems or cloud environments.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve this vulnerability. Monitor kernel logs for RPC over TLS handshake failures or race conditions in sunrpc module.

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