{"id":"CVE-2026-72221","title":"sunrpc: wait for in-flight TLS handshake callback when cancel loses race","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: wait for in-flight TLS handshake callback when cancel loses race\n\nWhen wait_for_completion_interruptible_timeout() in\nsvc_tcp_handshake() returns 0 (timeout) or…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < 0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9","Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < e0f4691d42a54d359d8b64509fd9ab938d4f2a33","Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < 65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b","Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < a4f878e8ecd729ccf2e50993444e217583adeace","Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < d00e32f84ca1a77cb67a3fbf59f58dada95f5a21","Linux 6.4"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T18:43:57.343257Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:45:02.148Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72221","references":[{"url":"https://git.kernel.org/stable/c/0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9"},{"url":"https://git.kernel.org/stable/c/e0f4691d42a54d359d8b64509fd9ab938d4f2a33"},{"url":"https://git.kernel.org/stable/c/65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b"},{"url":"https://git.kernel.org/stable/c/a4f878e8ecd729ccf2e50993444e217583adeace"},{"url":"https://git.kernel.org/stable/c/d00e32f84ca1a77cb67a3fbf59f58dada95f5a21"}],"tags":["cve.org"],"epss":0.00635,"epssPercentile":0.49342,"ingestedAt":"2026-10-16T19:46:24.422Z","slug":"CVE-2026-72221","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: wait for in-flight TLS handshake callback when cancel loses race\n\nWhen wait_for_completion_interruptible_timeout() in\nsvc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and\ntls_handshake_cancel() then returns false, handshake_complete() has\nwon the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and\nis about to invoke svc_tcp_handshake_done(), but the callback's\nside effects on xpt_flags and on svsk->sk_handshake_done have not\nyet committed.\n\nThe current code reads xpt_flags immediately to decide whether the\nsession succeeded. Two races result.\n\nIf the callback has executed set_bit(XPT_TLS_SESSION) but not yet\nclear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session,\nenqueues the transport, and returns. svc_xprt_received() then\nclears XPT_BUSY, a worker thread picks the transport up, the\ndispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set,\nand xpo_handshake is invoked a second time. That svc_tcp_handshake()\ncalls init_completion(&svsk->sk_handshake_done) while the original\ncallback concurrently calls complete_all() on it, corrupting the\nembedded swait_queue.\n\nIf the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet\nentered svc_tcp_handshake_done(), svc_tcp_handshake() reads\nXPT_TLS_SESSION as clear and tears the connection down even though\nthe handshake is about to succeed.\n\nWait for the callback to commit before inspecting xpt_flags. The\ncompletion is guaranteed to fire because handshake_complete()\ninvokes svc_tcp_handshake_done() unconditionally once it has set\nHANDSHAKE_F_REQ_COMPLETED.\n\n## Affected\n\n- `Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < 0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9`\n- `Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < e0f4691d42a54d359d8b64509fd9ab938d4f2a33`\n- `Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < 65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b`\n- `Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < a4f878e8ecd729ccf2e50993444e217583adeace`\n- `Linux >= b3cbf98e2fdf3cb147a95161560cd25987284330 < d00e32f84ca1a77cb67a3fbf59f58dada95f5a21`\n- `Linux 6.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}