From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97454][MODERATE REGULAR] ACPICA: add boundary checks in acpi_ps_get_next_field() [ Upstream Date: Thu, 24 Sep 2026 20:27:46 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97454 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: 1 X-AL-KERNEL-Commit: add715fc1ef5b0a71afe22b3f02aa28775d9ba62 List-Id: CVE: CVE-2026-97454 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ACPICA: add boundary checks in acpi_ps_get_next_field() [ Upstream Commit: add715fc1ef5b0a71afe22b3f02aa28775d9ba62 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=add715fc1ef5b0a71afe22b3f02aa28775d9ba62 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97454 Analysis date: Thu, 24 Sep 2026 20:27:46 -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-2026-97454 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97454 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-2026-97454 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97454 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:N/I:N/A:H';CWE-125;CWE-119;*CWE-20;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'An out of bounds read in ACPICA acpi_ps_get_next_field can occur when malformed or truncated AML data reaches field parsing without enough bytes remaining before aml_end. The affected parser may read an opcode, a NameSeg, field attributes, or an extended access length beyond the AML buffer. This can cause parser failure or a kernel crash if the read reaches inaccessible memory. No write primitive, information disclosure path, or privilege escalation primitive is demonstrated by this patch. The issue is not directly network reachable. For the CVSS the PR:L paranoid score assumes an attacker can influence supplied ACPI AML through a limited administrative environment, a virtualized platform management path, or another delegated configuration mechanism. In ordinary bare metal deployments, controlling ACPI firmware tables normally requires stronger administrative or physical control.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES OOB DANGER INIT SIMPLEFIX IMPROVEONLY DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH 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**:: Conservative arithmetic: +1 firmware mediated external input. Paranoid arithmetic: +1 firmware mediated external input, +1 plausible kernel crash from an out of bounds parser read. No floor or cap was applied. 2. Signal breakdown Positive signals: * +1 Firmware mediated external influence. ACPICA parses AML supplied through ACPI tables, normally originating from platform firmware or another firmware mediated source. This is not direct network reachability. * +1 Paranoid only. A malformed AML buffer can cause the parser to read beyond aml_end. If the read crosses into inaccessible memory, the result can be a kernel fault or crash. Important non-awarded signals: * Controlled reclaim not demonstrated. * Arbitrary write not demonstrated. * No use after free, double free, refcount mutation, or lifetime violation is established. * No user visible information disclosure path is demonstrated. * Confidentiality and integrity impact are not awarded because the patch establishes reads beyond AML bounds, not read back to userspace or modification of kernel memory. * Remote reachability is not established. ACPI AML reaches the parser through firmware or another platform controlled AML source, not ordinary network traffic. * Strong exploitation leverage is not demonstrated. * No authorization or security boundary bypass is demonstrated. * No reliable crash report, panic trace, or exploit PoC is supplied. The paranoid crash point is limited to the technically plausible fault consequence of the invalid read. No negative points were applied. Host administrator requirements, physical firmware update requirements, dynamic AML loading paths, and virtual platform management paths are not fully resolved by the supplied patch. 3. Reachability analysis The vulnerable function parses AML field encodings and previously read an opcode, NameSeg, field attributes, or extended access length without ensuring that sufficient bytes remained before parser_state->aml_end. The direct input is AML from ACPI tables. On ordinary bare metal systems, ACPI tables are generally firmware supplied, and altering them commonly involves firmware control, boot chain control, or an ACPI table override mechanism. However, the supplied patch does not establish the complete privilege requirements for all possible AML sources. Therefore HostAdminRequired is UNKNOWN rather than YES. No namespace scoped capability path is visible. The patch contains no network namespace, user namespace, configfs, ioctl, sysfs, or other attacker reachable userspace interface showing that an ordinary unprivileged process can supply AML to this parser. NamespaceScopedPrivilege is therefore UNKNOWN. There is no direct remote trigger. A malicious virtual platform, firmware update channel, boot environment, or privileged ACPI table override mechanism may be relevant deployment specific sources of malformed AML, but these are firmware mediated prerequisites rather than an Internet exposed kernel input path. No race is involved. The issue is deterministic once a truncated AML field reaches the parser. 4. Primitive and severity interpretation The exact primitive is a bounded out of bounds read in acpi_ps_get_next_field. Before the fix, the parser could dereference parser_state->aml when it was at or beyond aml_end, or read multi byte NameSeg and field attributes when too few bytes remained. This is not an active structured object use after free, fixed stale storage issue, repeated release, refcount mutation, overwrite, or type confusion. The patch only adds bounds checks and failure cleanup for a partially allocated parse object. PrimitiveClass is CLASS_C because the demonstrated behavior is invalid parser state and an invalid read that can at most cause parser failure or a kernel fault based on the supplied evidence. It is not CLASS_B because there is no lifetime corruption or stale object access. It is not CLASS_A because there is no controlled overwrite, controlled reuse, security boundary bypass, semantic reinterpretation, disclosure, or privilege escalation primitive. The practical demonstrated consequence is malformed AML rejection after the patch. Before the patch, malformed AML could cause an out of bounds read and potentially a crash. A confidentiality leak, kernel memory disclosure, integrity impact, and privilege escalation remain speculative and are not supported by a readback or corruption mechanism. ImportantCandidate is NO because the patch establishes only a limited parser out of bounds read without a useful post read primitive. AutoDowngradeAllowed is YES because no unresolved lifetime corruption, active object corruption, authorization bypass, controlled write, or security boundary primitive remains. Likely operational severity is Low to ordinary Moderate. The issue should receive a targeted manual review for product specific AML sources and firmware trust assumptions, but the supplied evidence does not support Important classification. 5. One-sentence report phrase A malformed or truncated ACPI AML field can cause acpi_ps_get_next_field to read beyond the AML buffer boundary, potentially resulting in parser failure or a kernel crash without a demonstrated disclosure or privilege escalation primitive. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Review whether the evaluated product permits untrusted or delegated parties to influence ACPI AML through firmware updates, ACPI table overrides, boot configuration, virtual machine platform management, or dynamically loaded AML tables. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ACPICA: add boundary checks in acpi_ps_get_next_field() [ Upstream Commit: add715fc1ef5b0a71afe22b3f02aa28775d9ba62 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=add715fc1ef5b0a71afe22b3f02aa28775d9ba62 Changed files: drivers/acpi/acpica/psargs.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=add715fc1ef5b0a71afe22b3f02aa28775d9ba62 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97454 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97454 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:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/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: 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: 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).