From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97445][MODERATE REGULAR] ACPICA: Enhance buffer validation in acpi_ut_walk_aml_resources() [ Upstream Date: Thu, 24 Sep 2026 18:40:36 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97445 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: 2 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: f65e2ef7ccca11dc874f48aff996a6a26528f8e7 List-Id: CVE: CVE-2026-97445 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ACPICA: Enhance buffer validation in acpi_ut_walk_aml_resources() [ Upstream Commit: f65e2ef7ccca11dc874f48aff996a6a26528f8e7 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f65e2ef7ccca11dc874f48aff996a6a26528f8e7 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97445 Analysis date: Thu, 24 Sep 2026 18:40:36 -0400 ActionableScore: 2 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-2026-97445 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97445 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-2026-97445 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97445 CHECK WITH IMPACT FROM ORIG NN MODERATE 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:N/A:H';CWE-125;*CWE-20;CWE-119;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.3';DESCR 'An out of bounds read can occur in ACPICA acpi_ut_walk_aml_resources when malformed AML resource descriptors are processed without confirming that the remaining buffer is large enough for all accessed fields. A short large resource descriptor can cause access to the serial bus type field beyond the supplied AML buffer. This may cause a kernel fault or crash when the kernel evaluates attacker controlled ACPI resource data. For the CVSS the PR:L paranoid score assumes a local actor can trigger evaluation of controlled or dynamically supplied ACPI resources in an environment with delegated ACPI related capabilities. The normal deployment case more commonly requires firmware control or administrative table loading. The issue is not directly network reachable. Impact is primarily denial of service. Limited confidentiality impact is retained only for the paranoid score because the defect is an out of bounds read. No integrity impact or privilege escalation primitive is demonstrated by the patch.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES OOB DANGER DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 2 * Conservative score: 2 * Raw paranoid score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate**:: No floor or cap was applied. 2. Signal breakdown * +1 Concrete out of bounds read: `acpi_ut_walk_aml_resources()` can access AML descriptor fields and calculate descriptor length before confirming that the remaining AML buffer is sufficiently large. * +1 Firmware mediated external input surface: AML resource data is normally supplied by platform firmware or equivalent ACPI table sources. This is not direct network reachability. * +0 Controlled reclaim, arbitrary write, type confusion, or lifetime corruption: not demonstrated. * +0 Confidentiality impact: no read back, userspace copy, network output, or other disclosure path is established. * +0 Integrity impact: the patch establishes validation of reads only. It does not establish an out of bounds write or modification of protected state. * +0 Reliable kernel crash: an invalid kernel read can fault, but the supplied patch does not demonstrate a reliable panic or host wide crash. * +0 Local unprivileged trigger: not established. The input may originate from firmware or privileged ACPI table injection mechanisms. * +0 Remote reachability: not established. * No privilege penalty was applied. The supplied evidence does not positively establish that host administrator privilege is required for every possible triggering path. * No race or niche subsystem penalty was applied. This is not a race, and ACPICA itself is broadly deployed even though attacker control of AML is not established. 3. Reachability analysis The vulnerable parser consumes AML resource descriptors associated with ACPI firmware tables and ACPI method evaluation. A malicious platform firmware image, malicious virtual firmware environment, or a privileged mechanism that injects or overrides ACPI tables could provide a truncated descriptor. The supplied patch does not establish that an ordinary local user can supply malformed AML resources to this parser. It also does not establish that host administrator privileges are always required, because the full set of AML providers and evaluation call sites is not included. Therefore HostAdminRequired is UNKNOWN rather than YES or NO. No relevant namespace scoped capability path is shown. There is no evidence that an attacker-created user namespace or network namespace can perform the complete malformed AML injection and evaluation sequence. NamespaceScopedPrivilege is UNKNOWN. No direct network service, packet parser, remotely exposed protocol listener, special hardware requirement, or timing race is established by the supplied evidence. 4. Primitive and severity interpretation The established primitive is an out of bounds read during AML resource descriptor parsing. Before the fix, a truncated small descriptor, truncated large descriptor, or descriptor with a claimed length exceeding the remaining AML buffer could cause ACPICA to inspect bytes beyond `end_aml` or pass an invalid descriptor range into subsequent processing. This is not a UAF, double free, refcount issue, active object lifetime violation, or ownership violation. It is also not an established out of bounds write. The patch adds length checks before field accesses and before accepting the descriptor length, which supports a read bounds validation interpretation. The appropriate classification is CLASS_C because the demonstrated behavior is invalid state handling with a possible kernel fault or DoS outcome. The patch does not establish meaningful exploitation leverage beyond the invalid read. A confidentiality consequence is possible only as an unsupported theoretical outcome unless a caller copies parsed data to an attacker-visible interface. Integrity impact, privilege escalation, controlled memory corruption, and arbitrary kernel read or write are not established. ImportantCandidate is NO because no Class A primitive or meaningful unresolved Class B lifetime or corruption primitive exists. AutoDowngradeAllowed is YES because the available evidence supports a constrained invalid-read issue without a demonstrated reusable corruption, authorization bypass, disclosure path, or boundary violation. 5. One-sentence report phrase An insufficient bounds check in ACPICA AML resource parsing can cause an out of bounds kernel read when malformed ACPI resource descriptors are evaluated, potentially causing a kernel fault or denial of service. 6. Manual review recommendation MANUAL CHECK RECOMMENDED The patch fixes a concrete kernel out of bounds read, but the supplied context does not show which AML sources are attacker controlled in the evaluated deployment or whether a reachable caller can expose parsed data. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ACPICA: Enhance buffer validation in acpi_ut_walk_aml_resources() [ Upstream Commit: f65e2ef7ccca11dc874f48aff996a6a26528f8e7 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f65e2ef7ccca11dc874f48aff996a6a26528f8e7 Changed files: drivers/acpi/acpica/utresrc.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=f65e2ef7ccca11dc874f48aff996a6a26528f8e7 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97445 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97445 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:L/UI:N/S:U/C:L/I:N/A:H The Best / paranoid CVSS score: 5.3 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: 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: 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).