* [CVE-2026-98003][LOW] iommu/amd: Do not reallocate GA log buffers on resume [ Upstream
@ 2026-09-25 18:58 21% AL-KERNEL
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From: AL-KERNEL @ 2026-09-25 18:58 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98003
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: iommu/amd: Do not reallocate GA log buffers on resume [ Upstream
Commit: 94458b80d3b203c1c9e2c98aa7319b7713e006c0
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=94458b80d3b203c1c9e2c98aa7319b7713e006c0
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98003
Analysis date: Fri, 25 Sep 2026 14:58:27 -0400
ActionableScore: 2
ActionableScore lower bound: 1
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-2026-98003 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98003
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-2026-98003 LOW https://www.kernelcve.org/list/?q=CVE-2026-98003 CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';*CWE-401;CWE-415;*CWE-416;**CWE-400;CWE-415;*CWE-416;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.8';DESCR 'AMD IOMMU GA log buffers can be allocated again on every system resume because iommu_init_ga_log is invoked from the virtual APIC enablement path and overwrites existing buffer pointers. Repeated suspend and resume cycles can therefore leak kernel memory and eventually cause resource exhaustion. A partial allocation failure can also leave a stale pointer after the allocated GA log buffer is freed, creating a possible double free or use after free cleanup condition that requires manual verification. For the CVSS the PR:L is selected for the paranoid score because a local user may be able to initiate suspend resume cycles through permitted desktop or service policy, although many server deployments require administrative power management privileges. The issue is not network reachable. Impact is primarily local denial of service, while limited confidentiality or integrity impact is conservatively retained only for the stale pointer error path.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES SIMPLEFIX LEAK LOG HARDWARE NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 2
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate**::
No floor or cap was applied.
2. Signal breakdown
Conservative signals:
* +1 Concrete persistent kernel resource leak. Each resume can replace the existing GA log and GA log tail pointers without freeing the prior allocations. Repeated suspend resume activity can accumulate unrecoverable kernel allocations.
Paranoid-only signal:
* +1 Weak invalid lifetime state. The partial allocation error path can free ga_log while leaving iommu->ga_log non-NULL. The patch clears this field, directly confirming prevention of a dangling pointer state. However, no supplied caller or control flow establishes a later dereference, second free, or refcount mutation through that pointer.
Non-awarded signals:
* No Real UAF signal. A freed pointer remaining stored is not by itself a UAF. The supplied patch does not establish a subsequent stale dereference or stale release.
* No concrete repeated release/refcount signal. The first free may occur in partial allocation cleanup, but a second lifetime-mutating operation on the exact same pointer is not shown.
* No controlled reclaim, object replacement, arbitrary write, information disclosure, integrity violation, callback control, or privilege escalation is demonstrated.
* No reliable kernel crash is established.
* No remote reachability is established.
* No local unprivileged trigger point is awarded. The input only suggests that a local user may be able to trigger suspend resume through deployment-specific policy, not that the complete vulnerable path is available to an ordinary user.
* No host-admin penalty is applied because host-admin-equivalent privilege is not positively established.
* No rare hardware penalty is applied. AMD IOMMU and AVIC related configuration are prerequisites, but the supplied evidence does not establish that an attacker cannot reach a configured affected machine.
3. Reachability analysis
The affected path is reached during system resume when AMD IOMMU virtual APIC support invokes iommu_init_ga_log. The vulnerable system must have the relevant AMD IOMMU, IRQ remapping, and guest interrupt remapping or AVIC support enabled.
The supplied evidence does not establish who can reliably trigger repeated suspend resume cycles. On many server systems, suspend and resume control is administrative. On some desktop or service-managed systems, a local user may be permitted to request suspend through policy. Therefore HostAdminRequired is UNKNOWN rather than YES or NO.
No network namespace, user namespace, delegated capability, or namespace-scoped complete trigger chain is shown. NamespaceScopedPrivilege is UNKNOWN. The issue is not directly network reachable.
4. Primitive and severity interpretation
The primary established defect is a repeatable memory leak caused by replacing GA log buffer pointers during resume. This is a resource-management issue and can cause availability degradation only after repeated resume cycles.
The patch also prevents a stale pointer from remaining after partial allocation cleanup. This is an invalid lifetime state, but the supplied diff does not establish the required second stage for a real UAF or double-free: a later dereference, free, put, refcount decrement, or structured use of the same stale pointer.
This is not an active structured-object UAF and not a concrete repeated lifetime mutation. The demonstrated primitive is therefore CLASS_C rather than CLASS_B. The practical consequence supported by the patch is memory leakage and potential resource exhaustion. A double-free or use-after-free is speculative without visible post-failure call sites.
ImportantCandidate is NO because meaningful post-lifetime exploitation leverage is not established. AutoDowngradeAllowed is YES because the currently supported impact is a resource leak plus a stale-pointer prevention fix, without demonstrated stale consumption or corruption.
5. One-sentence report phrase
Repeated system resume can leak AMD IOMMU GA log allocations, while a partial allocation failure can leave a stale GA log pointer that requires call-site review for possible later cleanup reuse.
6. Manual review recommendation
MANUAL CHECK RECOMMENDED
Review the iommu_init_ga_log error callers and all later free_ga_log call sites to determine whether a failed partial allocation can reach a second iommu_free_pages call on the same stale ga_log pointer.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: iommu/amd: Do not reallocate GA log buffers on resume [ Upstream
Commit: 94458b80d3b203c1c9e2c98aa7319b7713e006c0
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=94458b80d3b203c1c9e2c98aa7319b7713e006c0
Changed files:
drivers/iommu/amd/init.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=94458b80d3b203c1c9e2c98aa7319b7713e006c0
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98003 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98003
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:H/PR:L/UI:N/S:U/C:N/I:N/A:L
The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
The Best / paranoid CVSS score: 5.8
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: 1
Paranoid ActionableScore: 2
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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