CVE Intelligence
Unknown

CVE-2026-89566 — jbd2: check need_resched() when skipping busy checkpoint buffers

In the Linux kernel, the following vulnerability has been resolved: jbd2: check need_resched() when skipping busy checkpoint buffers journal_shrink_one_cp_list() skips busy checkpoint buffers when called with JBD2_SHRINK_BUSY_SKIP. The continue statement on this path also skips the need_resched() check at the end of the loop body. Consequently, when a checkpoint list contains mostly busy buffers, the shrinker can walk the entire list while holding journal->j_list_lock, even when a reschedule has been requested. Large checkpoint lists under memory pressure can therefore cause long lock hold times and leave other CPUs spinning on j_list_lock, resulting in soft lockups or RCU stalls. Route the busy-buffer path through the need_resched() check so that the shrinker can release j_list_lock and reschedule promptly, restoring parity with the clean-buffer path, which already checks need_resched(). This does not change which checkpoint buffers are eligible for removal.

Published Sep 11, 2026 · Updated Oct 21, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+2

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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.21%
ahead of 10% of scored CVEs · Oct 22, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ b98dba273a0e47dbfade89c9af73c5b012a4eabb and < f83c23286e54180cdc83a36463a60003534cc290≥ b98dba273a0e47dbfade89c9af73c5b012a4eabb and < f9182a85991a0ad5cd2940df6db75f40ad90028c≥ b98dba273a0e47dbfade89c9af73c5b012a4eabb and < 595cac7f1b32d009b97f83dd2b2d6a1a445e9bb4≥ b98dba273a0e47dbfade89c9af73c5b012a4eabb and < f213e12ff5c9590b1034ae8da0e6d09665c772d0version 9c31bb2684f8035beca0275349d19d679b679ffbversion 5fda50e262e65bd553ff777c4b280afd1495a18bversion 557fda9ed70ebf8eda2620ba3d746215285a1303≥ 5.15.129 and < 5.16
and 4 more ≥ 6.1.50 and < 6.2≥ 6.4.13 and < 6.5version 6.5≥ b98dba273a0e47dbfade89c9af73c5b012a4eabb and < dc7ece0b827fe3b748db685fb85cd2fc3710c3f9
Vulnerable CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 22, 2026 · 7 reading(s) · max 0.21%

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.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Received
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 19, 2026 – Oct 21, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

7 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99086 dm-integrity: validate the superblock on resume 14h
  • CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 14h
  • CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 14h
  • CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 14h
  • CVE-2026-99081 bnxt_en: fix DMA mapping length for padded small packets 14h
  • CVE-2026-99082 KVM: x86: Use active memslots for the per-vCPU MMIO cache 14h

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-2026-89566 is "jbd2: check need_resched() when skipping busy checkpoint buffers", 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 0.21% 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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