Time-of-check Time-of-use (TOCTOU) Affecting kernel-zfcpdump-core package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.15% (5th percentile)

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  • Snyk IDSNYK-RHEL10-KERNELZFCPDUMPCORE-19939144
  • published19 Sept 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

NewCVE-2026-89521  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-zfcpdump-core.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-zfcpdump-core package and not the kernel-zfcpdump-core package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

sched/core: Handle pick_task() releasing the rq lock

Core scheduling's pick_next_task() breaks when a ->pick_task() implementation can release the rq lock. The selection state derived on entry is only valid while the lock is held continuously. Once a pick can drop the lock, an interleaving selection can invalidate all of it: the single-CPU fast path can commit an uncookied pick although the core went cookied during the release, and forceidle committed by the interleaving selection skews the restarted pass's accounting.

Fix it by restarting the whole selection when a pick returns RETRY_TASK after releasing the lock: a single restart point above the state derivation replaces the per-loop restart labels, so a retry picks up state committed by interleaving selections and accounts and resets forceidle like a fresh selection would.

need_sync and fi_before latch across retries. Clock validity can't be re-derived - there is no program-ordered way to tell whether the own and core rq clocks are still updated after the lock was released, as other lockers' pin cycles may or may not have invalidated them. When restarting, clear core_clock_updated so that the sibling loop re-updates the core rq, and update the own rq clock if invalidated.

CVSS Base Scores

version 3.1