kprobes: Protect kprobe_blacklist with RCU

Answer in brief

CVE-2026-89988 records a Unknown severity vulnerability in kprobes: Protect kprobe_blacklist with RCU. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 16, 2026Updated Sep 16, 2026Source checked Sep 16, 2026First seen by HOL Sep 16, 2026Material review Sep 16, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=376e242429bf8539ef39a080ac113c8799840b13 <8f406205003f741225f620f0e357ca0de71d45e3 \|\| >=376e242429bf8539ef39a080ac113c8799840b13 <630ed8734a02b992e8a97538179c2ece42c5210f \|\| >=376e242429bf8539ef39a080ac113c8799840b13 <518d9b5568bb06f86e4434f7a30faa9612ea91ad \|\| >=376e242429bf8539ef39a080ac113c8799840b13 <5da247e4d1e8661d4d6f997101d59967e8994e32 \|\| >=376e242429bf8539ef39a080ac113c8799840b13 <6e62cf983a2bd547e6bbd3f935539233e5f97f8f \|\| >=376e242429bf8539ef39a080ac113c8799840b13 <0c4256196b3a105307e2235fbfd85e768bbcdd0f	8f406205003f741225f620f0e357ca0de71d45e3, 630ed8734a02b992e8a97538179c2ece42c5210f, 518d9b5568bb06f86e4434f7a30faa9612ea91ad, 5da247e4d1e8661d4d6f997101d59967e8994e32, 6e62cf983a2bd547e6bbd3f935539233e5f97f8f, 0c4256196b3a105307e2235fbfd85e768bbcdd0f
Linux/Linuxgeneric	3.16	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 8f406205003f741225f620f0e357ca0de71d45e3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 16, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: kprobes: Protect kprobe_blacklist with RCU __within_kprobe_blacklist() traverses kprobe_blacklist without holding kprobe_mutex. When a module is unloaded, kprobe_remove_area_blacklist() removes blacklist entries and immediately frees them with kfree(). A concurrent call to within_kprobe_blacklist() can therefore dereference freed memory. Furthermore, within_kprobe_blacklist() can be called in atomic or non-preemptible contexts where the sleeping kprobe_mutex cannot be taken. Protect kprobe_blacklist with RCU. Use guard(rcu)() and list_for_each_entry_rcu() for traversal, list_add_tail_rcu() for insertions, list_del_rcu() for deletions, and kfree_rcu() to reclaim entries safely after a grace period.

Quoted source text, attributed separately from HOL analysis.