CVE-2026-89536

Published: September 15, 2026Last modified: September 28, 2026

Description

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: wait for in-flight client TLS handshake callback xs_tls_handshake_sync() gives xs_tls_handshake_done() a reference to the lower transport before submitting the handshake request. On timeout or signal, the synchronous waiter drops that reference after calling tls_handshake_cancel(). handshake_req_cancel() returns false when handshake_complete() has already marked the request complete. In that case the completion callback can still be running, so dropping the callback-owned reference in the waiter can free the lower transport before xs_tls_handshake_done() stores xprt_err or drops its own reference. If cancellation loses to completion, wait until xs_tls_handshake_done() signals handshake_done and let the callback release its reference. This mirrors the server-side handshake lifetime handling and keeps the timeout or signal return value unchanged.

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References

• https://git.kernel.org/stable/c/15431820f448e09f8029b670d5c82aa5917d4625
• https://git.kernel.org/stable/c/1de391e8b94e31b45c19c16dbf315e294810c7de
• https://git.kernel.org/stable/c/7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b
• https://git.kernel.org/stable/c/a89dd597458848b463d284b15e42a8078beeb046
• https://git.kernel.org/stable/c/fb43997407bc17ee39bac81ab708101312e255f5