From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97449][MODERATE REGULAR] ACPICA: Add package limit checks in parser functions [ Upstream Date: Thu, 24 Sep 2026 18:55:58 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97449 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 1 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 250800658bf3db32e7accc615b0a134c30fba203 List-Id: CVE: CVE-2026-97449 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ACPICA: Add package limit checks in parser functions [ Upstream Commit: 250800658bf3db32e7accc615b0a134c30fba203 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=250800658bf3db32e7accc615b0a134c30fba203 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97449 Analysis date: Thu, 24 Sep 2026 18:55:58 -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-2026-97449 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97449 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: MODERATE REGULAR 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-2026-97449 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97449 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H';CWE-125;*CWE-20;CWE-1284;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'Malformed ACPI AML package length fields can cause ACPICA parser pointers to move outside the valid AML buffer during package parsing. Subsequent parsing may perform an out of bounds access and can cause a kernel crash. For the CVSS the PR:H is selected because reliable triggering normally requires control over firmware supplied AML or administrative capability to install a custom ACPI table or method. The issue is not directly network reachable. Impact is at least local denial of service. The paranoid score includes limited confidentiality impact because an out of bounds read is present, but no write primitive or privilege escalation path is demonstrated by the patch.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) YES OOB DANGER IMPROVEONLY LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=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: 1 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate**:: The score reflects a concrete parser bounds-validation defect and potential kernel fault, but no established attacker-controlled write, disclosure path, lifetime violation, authorization bypass, or below-host-admin trigger. 2. Signal breakdown * +1 Weak parser memory-safety concern. Malformed AML package lengths can cause parser pointers such as aml or pkg_end to move outside the validated AML buffer before subsequent parser operations consume them. * +0 Reliable kernel crash not awarded. The patch prevents out-of-bounds access, but the supplied commit does not demonstrate a reproducible panic, Oops, or host-wide failure. * +0 Remote reachability not established. AML is firmware-mediated input and is not directly reachable through network traffic. * +0 Local unprivileged trigger not established. The supplied material does not prove that an ordinary local user can install arbitrary AML or invoke the affected parser paths. * +0 Firmware-mediated external influence not awarded. Firmware is an AML source, but attacker control of firmware or a device-provided ACPI table is not established. * +0 Confidentiality impact not awarded. The patch establishes an out-of-bounds parser access, but no bytes are shown to be copied to userspace, a device, logs, or a network peer. * +0 Integrity impact not awarded. No out-of-bounds write, pointer overwrite, active-object corruption, or semantic ownership violation is shown. * +0 Strong exploitation leverage not awarded. Controlled reclaim, arbitrary read or write, callback influence, type confusion, and privilege escalation are not established. * +0 Race penalty not applicable. This is input validation and parser-boundary handling, not a timing-dependent race. * +0 host-admin penalty not applied. Host-admin-equivalent privilege is plausible for runtime AML installation, but is not positively established for every affected AML input path. 3. Reachability analysis The vulnerable parser consumes AML supplied by platform ACPI tables and may also process dynamically installed ACPI methods through paths including acpi_install_method. Platform firmware AML is normally trusted by the running operating system. A malicious virtual-machine monitor can provide malicious ACPI tables to a guest, but that attacker already controls the guest platform and this does not establish a guest-to-host attack. Runtime installation of custom AML methods is generally an administrative operation, but the supplied patch does not include the relevant interface, capability checks, configuration dependencies, or callers. Therefore HostAdminRequired is UNKNOWN rather than YES. There is no evidence that the complete trigger is available in an attacker-created namespace, so NamespaceScopedPrivilege is UNKNOWN. No special hardware, network packet path, or timing race is required by the parser flaw itself. However, practical attacker control of the AML source is unresolved and is the main reachability limitation. 4. Primitive and severity interpretation The patch establishes an out-of-bounds parser-pointer condition. A malformed AML package length can make acpi_ps_get_next_package_end return a pointer beyond aml_end or before the valid current parsing position. The subsequent parser logic may then consume malformed memory as AML data. This is not a UAF, double free, refcount bug, stale-object lifetime violation, or active-object replacement issue. No concrete repeated release or refcount mutation exists. The established primitive is best classified as CLASS_C because the supported consequence is invalid parser state and a possible kernel fault without an independently useful corruption primitive. The patch does not establish an out-of-bounds write, controlled target selection, user-visible information disclosure, privilege escalation, or authorization bypass. The paranoid interpretation does not increase the ActionableScore because limited out-of-bounds reading alone does not establish a disclosure channel or meaningful post-fault exploitation leverage. ImportantCandidate is NO because no Class A or materially unresolved Class B lifetime or corruption primitive is present. AutoDowngradeAllowed is YES because the demonstrated issue is a constrained parser bounds defect without established write, reuse, disclosure, or security-boundary effects. 5. One-sentence report phrase Malformed ACPI AML package lengths can move ACPICA parser pointers outside the valid AML buffer and may cause an invalid memory access or kernel denial of service, but no write primitive, information disclosure path, or privilege escalation mechanism is established. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Confirm the reachable AML sources and their authorization boundaries in the evaluated product, especially runtime custom-method interfaces, ACPI table override mechanisms, firmware-update paths, and virtual-machine firmware provisioning. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ACPICA: Add package limit checks in parser functions [ Upstream Commit: 250800658bf3db32e7accc615b0a134c30fba203 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=250800658bf3db32e7accc615b0a134c30fba203 Changed files: drivers/acpi/acpica/nsxfname.c drivers/acpi/acpica/psargs.c drivers/acpi/acpica/psloop.c drivers/acpi/acpica/psparse.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=250800658bf3db32e7accc615b0a134c30fba203 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97449 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97449 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H The Best / paranoid CVSS score: 4.7 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: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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 alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).