CVE-2026-89589 — acpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks
In the Linux kernel, the following vulnerability has been resolved: acpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks The CXL CPER work registration and unregistration helpers acquire cxl_cper_work_lock and cxl_cper_prot_err_work_lock with a spinlock guard(), which leaves local interrupts enabled. The corresponding post paths (cxl_cper_post_event(), cxl_cper_post_prot_err()) execute in hard IRQ context (they are called from the GHES error notification path) and acquire the same locks with an irqsave guard(). If a CPU is holding one of these locks via a spinlock guard() when a GHES interrupt arrives on the same CPU, the IRQ handler spins on the held lock waiting for it to release, while the lock holder is preempted by the IRQ. The result is a deadlock. Convert both locks from spinlock_t to raw_spinlock_t and use guard() at all call sites. On PREEMPT_RT kernels spinlock_t is backed by rt_mutex and sleeping from hard IRQ context is not permitted; raw_spinlock_t is safe in both contexts. Add WARN_ONCE to both register functions to surface double-registration bugs at runtime. Restructure both unregister functions to clear the global work pointer under the lock before calling cancel_work_sync(), closing the window where a CPER interrupt could schedule work on a pointer about to be freed. Add kfifo_reset() after cancel_work_sync() so stale entries are not replayed on next module load. Both kfifos are single-consumer: only one work_struct is registered at a time, enforced by the WARN_ONCE guard in the register functions. kfifo_reset() is safe outside the lock because cancel_work_sync() has already quiesced the consumer, and no new consumer can register until the current module exit completes and a fresh module init runs. Remove the redundant cancel_work_sync() call from cxl_ras_exit() and cxl_pci_driver_exit(). The CPER unregister functions now quiesce the work internally.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 and < cbc27a4302a1feb0ff77c1755021837a738b0ce9≥ 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 and < c735dbce7ad03df708bf22ec964f67e43cbc823a≥ 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 and < 0e25382b05de48d09b243d3d447d236a6d735bc2≥ 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 and < 6625ca499c3131ef63be3215f8f942d7a097ea3aversion 6.10 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 23, 2026 · 8 reading(s) · max 0.18%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
6 on the record
- git.kernel.org/stable/c/cbc27a4302a1feb0ff77c1755021837a738b0ce9
- nvd.nist.gov/vuln/detail/CVE-2026-89589
- git.kernel.org/stable/c/0e25382b05de48d09b243d3d447d236a6d735bc2
- git.kernel.org/stable/c/6625ca499c3131ef63be3215f8f942d7a097ea3a
- git.kernel.org/stable/c/c735dbce7ad03df708bf22ec964f67e43cbc823a
- github.com/advisories/GHSA-9wp4-w6jg-245j
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99086 dm-integrity: validate the superblock on resume 1d
- Unknown CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 1d
- Unknown CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 1d
- Unknown CVE-2026-99084 readdir: take no inode lock on an immutable directory 1d
- Unknown CVE-2026-99085 sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler 1d
- Critical CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-89589 is "acpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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