null_blk: free zones array on device power-off

Answer in brief

CVE-2026-90187 records a Unknown severity vulnerability in null_blk: free zones array on device power-off. 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 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 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	>=ca4b2a011948fae4e4d31490107db4926385a983 <056be41932c95aabdb3c2967d1ef4978f17a0225 \|\| >=ca4b2a011948fae4e4d31490107db4926385a983 <b2437d37fcc31fce8a5da1cc1739e284814d2491 \|\| >=ca4b2a011948fae4e4d31490107db4926385a983 <0a3afab87124171022fb3579502fa38ef5b311c9 \|\| >=ca4b2a011948fae4e4d31490107db4926385a983 <2a6357a9b935a34f5508618fee8a7fffbf7722a8	056be41932c95aabdb3c2967d1ef4978f17a0225, b2437d37fcc31fce8a5da1cc1739e284814d2491, 0a3afab87124171022fb3579502fa38ef5b311c9, 2a6357a9b935a34f5508618fee8a7fffbf7722a8
Linux/Linuxgeneric	4.19	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 056be41932c95aabdb3c2967d1ef4978f17a0225 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: null_blk: free zones array on device power-off null_init_zoned_dev() allocates dev->zones when a zoned device is powered on, but null_del_dev() never frees it on power-off; dev->zones is only freed later in null_free_dev(), when the configfs directory is removed. If the device is powered off and then on again, null_init_zoned_dev() allocates a new array and overwrites the dev->zones pointer, leaking the previous allocation each power cycle. Free dev->zones in null_del_dev() via null_free_zoned_dev() to solve it. And calling null_free_zoned_dev() in null_free_dev() is no longer necessary because every caller already invokes null_del_dev() first: via nullb_group_drop_item() before nullb_device_release(), in the null_add_dev() error path of null_create_dev(), and in null_destroy_dev(). Remove the redundant call. And take &lock around zone_cond_store() in the two store wrappers to serialize dev->zones check-and-deref against its alloc/free, which already run under &lock. The reason there was no problem before is that only nullb_device_release() or null_exit() frees the dev->zones, which guarantees that subsequent users won't access the configfs interface.

Quoted source text, attributed separately from HOL analysis.