* [CVE-2026-90275][LOW] md/raid1: don't set array_frozen in raid1_takeover() [ Upstream
@ 2026-09-18 7:28 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-18 7:28 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-90275
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: md/raid1: don't set array_frozen in raid1_takeover() [ Upstream
Commit: 668d99ba47210ab6ceb18f1cf022c0accca7e3bb
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=668d99ba47210ab6ceb18f1cf022c0accca7e3bb
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90275
Analysis date: Fri, 18 Sep 2026 03:28:31 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-90275 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90275
The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.
The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.
Published priority for this report: LOW
Manual review required: NO
A detailed explanation of the methodology and priority rules is included
at the end of this message.
======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================
CVE-2026-90275 LOW https://www.kernelcve.org/list/?q=CVE-2026-90275 CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-665;CWE-667;**CWE-400;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'A logic bug in md raid1 takeover can leave the new RAID1 configuration with array_frozen set after the takeover path completes. Once _wait_barrier observes this stale frozen state, I/O to the affected array can stall permanently and cause denial of service for storage backed by that md device. For the CVSS the PR:L is used in the paranoid score because a reduced capability root, storage service account, or delegated administrator may be able to trigger RAID takeover without full host control. The issue is not network reachable and is triggered through local md control plane operations such as RAID level takeover or related array management. Impact is availability loss only. There is no evidence of memory corruption, information disclosure, or privilege escalation from the patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) YES DISK LEAK LINUS INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=YES
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate**::
No floor or cap changed the score.
2. Signal breakdown
* +1: Persistent storage availability impact. The stale `array_frozen` state can make every I/O to the affected RAID1 array stall permanently after `_wait_barrier()` observes it.
* +1: Important storage path. The bug is in md RAID1 takeover handling and can affect storage backed by the md device.
* -2: Host-admin-equivalent privilege is required. RAID level takeover and md array management are host storage administration operations, normally performed via mdadm or privileged sysfs control.
Important non-awarded signals:
* RealUAF not awarded. The patch shows a stale logical state flag, not post-lifetime object use.
* Memory corruption not awarded. No UAF, OOB access, double free, refcount misuse, or active object corruption is established.
* Confidentiality and integrity not awarded. The demonstrated effect is I/O stall only.
* Remote reachability not awarded. The trigger is local md control-plane management, not packet or network data-plane input.
* Privilege escalation not awarded. No exploitation primitive beyond availability loss is shown.
* Extra availability point not awarded beyond the storage DoS and important storage-path signal to avoid overstating a host-admin-triggered device outage.
* Manual review escalation not awarded because the issue is a logic/configuration-state DoS with no unresolved corruption, ownership, authorization, or lifetime primitive.
3. Reachability analysis
The realistic trigger is a local md RAID management operation that performs RAID1 takeover. This normally requires host administrator or equivalent storage-management privilege. There is no evidence that an ordinary local user can perform the complete operation.
Namespace-scoped privilege is not established. md array takeover is tied to host block-device and storage control rather than an attacker-created user or network namespace. No network trigger is present. No special rare hardware is required beyond use of md RAID1 and a takeover path affected by the regression. This is not a race. It is an ordered state-management bug where `array_frozen` is set and then no longer cleared after the referenced md suspend behavior change.
4. Primitive and severity interpretation
The exact primitive is a stale invalid kernel storage state: `raid1_takeover()` sets `conf->array_frozen = 1` on a newly allocated `r1conf`, and after the behavioral change in `mddev_suspend()` nothing clears it. The consequence is that `_wait_barrier()` can block all I/O to the array.
This is CLASS_C because the demonstrated behavior is invalid-state DoS without a meaningful corruption or lifetime primitive. It is not active structured UAF, not fixed stale storage UAF, and not a repeated release/refcount case. There is no first release that may end lifetime, no surviving dangling reference, and no second lifetime mutation.
ImportantCandidate is NO because the patch supports availability impact only and does not establish memory corruption, authorization bypass, ownership violation, or plausible privilege escalation. AutoDowngradeAllowed is YES because no meaningful unresolved Important-grade primitive remains after the demonstrated storage DoS is accounted for.
Likely operational severity is ordinary Moderate or Low-like for security triage, despite potentially severe operational impact if the affected md array backs important services.
5. One-sentence report phrase
A logic bug in md RAID1 takeover can leave the array permanently frozen after takeover, causing all I/O to the affected md device to stall, but triggering requires local host storage administration privileges and no memory corruption or privilege escalation primitive is established.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
Reason: the issue is a host-admin-triggered RAID1 control-plane availability bug with no UAF, no memory corruption, no authorization bypass, and no remote or unprivileged trigger shown.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: md/raid1: don't set array_frozen in raid1_takeover() [ Upstream
Commit: 668d99ba47210ab6ceb18f1cf022c0accca7e3bb
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=668d99ba47210ab6ceb18f1cf022c0accca7e3bb
Changed files:
drivers/md/raid1.c
Diff excerpt:
Not included in this email. See the upstream URL for the full patch.
Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=668d99ba47210ab6ceb18f1cf022c0accca7e3bb
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-90275 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90275
The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.
The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.
The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.
Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:
Conservative CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
The Best / paranoid CVSS score: 5.5
The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.
CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.
A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.
Conservative ActionableScore: unknown
Paranoid ActionableScore: 1
The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.
For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:
ActionableScore below 5 -> MODERATE REGULAR
ActionableScore 5 or more -> MODERATE 7.0
The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.
There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).
KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.
AL-KERNEL base severity for this report: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW
These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).
Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
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