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CVE-2026-89681

nfsd: fix layout fence worker double-reference race PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix layout fence worker double-reference race The workqueue core clears WORK_STRUCT_PENDING before the callback is invoked, so delayed_work_pending() in lm_breaker_timedout() can return false while the fence worker is already running. This lets the breaker take a duplicate sc_count reference and schedule a new worker that coalesces with the in-progress one. The extra reference is never put, leaking the layout stateid. Replace the racy delayed_work_pending() check with an ls_fence_inflight boolean set atomically with refcount_inc_not_zero() under ls_lock, and cleared under ls_lock before the final nfs4_put_stid() on the dispose path; the retry path intentionally retains it. Remove the self-rearm mod_delayed_work() at the top of the worker.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected f52792f484ba2316853736856dde19b7e7458861 before a278d361e0e8f242211891193d56483a7a9f47a8; affected f52792f484ba2316853736856dde19b7e7458861 before 8580571227451384399b3fa53fcde19848c48e5a
Linux / Linuxaffected 7.1; unaffected 0 before 7.1; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References