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CVE-2026-72221

sunrpc: wait for in-flight TLS handshake callback when cancel loses race PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected b3cbf98e2fdf3cb147a95161560cd25987284330 before 0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9; affected b3cbf98e2fdf3cb147a95161560cd25987284330 before e0f4691d42a54d359d8b64509fd9ab938d4f2a33; affected b3cbf98e2fdf3cb147a95161560cd25987284330 before 65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b; affected b3cbf98e2fdf3cb147a95161560cd25987284330 before a4f878e8ecd729ccf2e50993444e217583adeace; affected b3cbf98e2fdf3cb147a95161560cd25987284330 before d00e32f84ca1a77cb67a3fbf59f58dada95f5a21
Linux / Linuxaffected 6.4; unaffected 0 before 6.4; unaffected 6.6.145 through 6.6.*; unaffected 6.12.97 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.