VulnerabilityPublished 17 Sep 2026Updated 30 Oct 2026

CVE-2026-90187: Linux kernel · null_blk: free zones array on device power-off

Source GCVE Database

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Authoritative record:CVE-2026-90187· Medium

Not known to be exploited · fixed in b2437d37fcc31fce8a5da1cc1739e284814d2491 : update Linux kernel when convenient.

Data as of 30 Oct 2026, 19:03 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in b2437d37fcc31fce8a5da1cc1739e284814d2491, 056be41932c95aabdb3c2967d1ef4978f17a0225, 26d21585caa61c30d0f3044a1e6d172456148c9f +3

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-45hh-qmfr-m7pj

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < b2437d37fcc31fce8a5da1cc1739e284814d2491	Fixed in b2437d37fcc31fce8a5da1cc1739e284814d2491
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < 056be41932c95aabdb3c2967d1ef4978f17a0225	Fixed in 056be41932c95aabdb3c2967d1ef4978f17a0225
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < 26d21585caa61c30d0f3044a1e6d172456148c9f	Fixed in 26d21585caa61c30d0f3044a1e6d172456148c9f
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < 08a31a2cc3d1cea67ccd292d01511cd0a72d4656	Fixed in 08a31a2cc3d1cea67ccd292d01511cd0a72d4656
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < 2a6357a9b935a34f5508618fee8a7fffbf7722a8	Fixed in 2a6357a9b935a34f5508618fee8a7fffbf7722a8
LinuxLinux	Affected ≥ ca4b2a011948fae4e4d31490107db4926385a983, < 0a3afab87124171022fb3579502fa38ef5b311c9	Fixed in 0a3afab87124171022fb3579502fa38ef5b311c9

AI-suggested

A fix is available that frees the zones array during device removal and improves locking to prevent concurrent access issues. Users should apply the updated Linux kernel version containing this fix. Since this is a kernel-level fix, upgrading to the patched kernel release is the recommended remediation.

Description

A memory leak vulnerability exists in the Linux kernel's null_blk driver related to the handling of the zones array during device power cycles. The zones array allocated when a zoned device powers on is not freed on power-off, causing repeated allocations to leak memory on each power cycle. The issue is addressed by freeing the zones array during device removal and adjusting locking to prevent concurrent access issues.

Impact

The vulnerability causes a memory leak in the Linux kernel null_blk driver when zoned devices are power-cycled. This leak occurs because allocated memory for the zones array is not freed on device power-off, potentially leading to increased memory consumption over time. There is no indication of code execution or privilege escalation. No known exploits in the wild have been reported.

Summary

The Linux kernel null_blk driver allocates a zones array in null_init_zoned_dev() when a zoned device powers on but does not free this array in null_del_dev() on power-off, only freeing it later in null_free_dev() when the configfs directory is removed. This leads to a memory leak if the device is powered off and on repeatedly, as the zones pointer is overwritten without freeing the previous allocation. The fix involves freeing dev->zones in null_del_dev() via null_free_zoned_dev() and removing redundant calls to null_free_zoned_dev() in null_free_dev(). Additionally, locking is added around zone_cond_store() to serialize access and prevent race conditions. This resolves the memory leak and ensures safe concurrent access to dev->zones.

References

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