* [CVE-2026-80913][LOW] selinux: require every boolean value to be defined
@ 2026-09-04 22:39 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-04 22:39 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-80913
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: selinux: require every boolean value to be defined
Commit: 4d0ece18e648bd4362704fd087249ac697f2b7fb
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4d0ece18e648bd4362704fd087249ac697f2b7fb
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80913
Analysis date: Fri, 04 Sep 2026 18:39:26 -0400
ActionableScore: 0
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-2026-80913 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80913
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-2026-80913 LOW https://www.kernelcve.org/list/?q=CVE-2026-80913 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-20;**CWE-476;CWE-754;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 malformed SELinux policy image can declare more boolean values than it actually defines, leaving NULL entries in the bool_val_to_struct array. Later SELinux code paths such as cond_evaluate_expr(), security_get_bools(), security_get_bool_value(), and security_set_bools() may walk the array by index and dereference those NULL entries, causing a kernel crash. For the CVSS the PR:L is used in the paranoid score only for deployments where SELinux policy loading is delegated to a non root management service or reduced capability administrator. In typical host deployments the required privilege is closer to PR:H because loading SELinux policy is an administrative operation. The issue is not network reachable and requires local ability to provide or load a malformed policy image. Impact is denial of service via NULL pointer dereference, with no supported evidence of information disclosure, integrity impact, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) SKIP CVE-2026-80913 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: url YES NO NO unknown MAYBE DISK LINUS INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=0
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=YES
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: -1
* Conservative score: 0
* Raw paranoid score: -1
* Paranoid score: 0
* Final recommended bucket: **Ordinary Moderate**::
Applied normalization: raw score -1 -> 0 because the ActionableScore floor is treated as 0.
2. Signal breakdown
Positive signals:
* +1 Reliable kernel crash / strong DoS: malformed SELinux policy data can leave NULL entries in bool_val_to_struct, and later SELinux paths can dereference those entries, causing a NULL pointer dereference.
Negative signals:
* -2 Full host-admin-equivalent privilege: the trigger requires loading or replacing SELinux policy on the host, which is a host security-administration operation.
Non-awarded material signals:
* +0 Real UAF: not awarded. No use-after-free or stale post-lifetime object use is established.
* +0 Concrete repeated release/refcount: not awarded. No put, release, free, or refcount mutation through a dangling reference is present.
* +0 Controlled reclaim or arbitrary write: not demonstrated.
* +0 Confidentiality or integrity: not awarded. The established consequence is NULL pointer dereference, not information disclosure, policy bypass, or attacker-controlled modification.
* +0 Remote reachability: not established. The issue is triggered by local policy loading, not packet processing.
* +0 Security-boundary bypass: not awarded. The malformed policy can crash the kernel after being accepted far enough into indexing, but no unauthorized access decision or LSM bypass is established.
* +0 Extra availability: not awarded because the same kernel crash is already counted once.
* Validation-only cap is not needed. The patch is validation-oriented, but a concrete NULL dereference consequence is described, and the raw score is already below any cap.
3. Reachability analysis
The attacker must be able to supply and load a malformed SELinux policy image where p_bools.nprim declares boolean values that are not actually defined. In normal Linux deployments, loading SELinux policy is restricted to host security administration, commonly root or an equivalent privileged policy-management domain.
Ordinary local user reachability is not established. Namespace-scoped triggering is not established because SELinux policy loading is not a normal per-user-namespace or per-network-namespace operation. There is no network trigger and no special hardware requirement. No race or timing dependency is involved.
HostAdminRequired is YES because the complete trigger requires host-level SELinux policy loading privileges. NamespaceScopedPrivilege is NO.
4. Primitive and severity interpretation
The exact primitive is an invalid NULL pointer dereference caused by incomplete validation of boolean definitions during SELinux policy indexing. The policy image can create sparse boolean value space, leaving NULL entries in bool_val_to_struct. Later consumers walk that array by index and dereference entries without a NULL-tolerant predicate.
This is not an active structured UAF and not fixed stale storage. It is a validation failure leading to invalid state and crash. There is no concrete repeated release/refcount operation. There is no first lifetime operation that may free an object and no second lifetime mutation through the same dangling reference.
PrimitiveClass is CLASS_C because the demonstrated behavior is crash/DoS via NULL dereference without an independently useful corruption primitive. The demonstrated consequence is kernel crash. The speculative consequence of stronger exploitation is unsupported by the patch context. ImportantCandidate is NO because there is no memory corruption, ownership violation, authorization bypass, controlled write, disclosure, or unresolved lifetime primitive. AutoDowngradeAllowed is YES because the issue is host-admin-triggered DoS with no meaningful unresolved exploitation leverage.
Likely operational severity is ordinary Moderate or Low-like in practical triage, despite a CVSS-style DoS vector possibly reaching Medium.
5. One-sentence report phrase
A malformed SELinux policy can leave undefined boolean entries in bool_val_to_struct and later cause a kernel NULL pointer dereference, but triggering requires host-level SELinux policy loading privileges and the supported impact is denial of service only.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
Reason: this is a host-admin-gated malformed policy validation issue with a NULL pointer dereference DoS and no evidence of UAF, memory corruption, privilege escalation, information disclosure, or security-boundary bypass.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: selinux: require every boolean value to be defined
Commit: 4d0ece18e648bd4362704fd087249ac697f2b7fb
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4d0ece18e648bd4362704fd087249ac697f2b7fb
Commit description:
p_bools.nprim comes from the policy image independently of how many
booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at
value - 1, so a count larger than the values present leaves NULL entries.
Every user of that array then walks it by index and dereferences each
entry: cond_evaluate_expr() on the access-vector path,
security_get_bools() and security_get_bool_value() behind selinuxfs, and
security_set_bools(). A sparse class value is absorbed by
policydb_class_isvalid() and its siblings; booleans have no such
predicate, and no consumer that could use one.
Reject a boolean value that no boolean defines, once, where the array is
built. Conforming policies define every boolean they declare and are
unaffected.
Cc: [email protected]
Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Bryam Vargas <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Signed-off-by: Paul Moore <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
security/selinux/ss/policydb.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=4d0ece18e648bd4362704fd087249ac697f2b7fb
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80913 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80913
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: 0
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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