From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97451][MODERATE REGULAR] ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) [ Upstream Date: Thu, 24 Sep 2026 21:21:41 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97451 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: 3 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: d0d89f2e16a874e0f8fb17045da293e8bedf8b21 List-Id: CVE: CVE-2026-97451 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) [ Upstream Commit: d0d89f2e16a874e0f8fb17045da293e8bedf8b21 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d0d89f2e16a874e0f8fb17045da293e8bedf8b21 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97451 Analysis date: Thu, 24 Sep 2026 21:21:41 -0400 ActionableScore: 3 ActionableScore lower bound: 2 Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97451 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97451 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: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-97451 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97451 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:H/UI:N/S:U/C:L/I:N/A:H';CWE-190;CWE-125;CWE-195;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'An integer overflow in the ACPICA Mid opcode can occur when Index plus Length wraps during truncation checks. The overflow can bypass length limiting and pass an invalid large size to memcpy while processing an AML String or Buffer operation. This may cause an out of bounds read or a kernel crash when malicious or malformed AML is evaluated. For the CVSS the PR:H reflects that reliable triggering normally requires control over AML input, ACPI tables, firmware, or a privileged table loading mechanism. The issue is not directly network reachable. The base impact is denial of service. The paranoid score also includes limited confidentiality impact because an out of bounds read may expose adjacent memory through AML results, but no out of bounds write or privilege escalation primitive is demonstrated.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3) YES DANGER SIMPLEFIX IMPROVEONLY NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 ActionableScoreLower=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: 3 * Paranoid score: 3 * Final recommended bucket: **Borderline / manual review recommended**:: No floor or cap was applied. 2. Signal breakdown Conservative signals: * +1 Weak invalid-memory-access concern. The overflow check prevents Index plus Length wrapping and bypassing truncation before memcpy. This establishes a potential oversized or otherwise invalid memcpy length, but the supplied patch does not establish an attacker-controlled write target or payload. * +1 Potential kernel crash or strong DoS. Passing an invalid wrapped length to memcpy can plausibly cause an invalid memory access and kernel fault during AML evaluation. Paranoid-only signal: * +1 Firmware-mediated external influence. AML commonly originates from firmware-provided ACPI tables. A malicious or malformed AML method can be relevant input, although this is not direct remote reachability and control of firmware or injected ACPI tables is not established for an ordinary attacker. Important non-awarded signals: * +0 Real UAF. No freed object, dangling reference, stale post-lifetime access, or refcount misuse is established. * +0 OOB write. The patch indicates an invalid memcpy size, but the visible context does not establish that the destination allocation or destination object can be overrun. * +0 Controlled reclaim, object replacement, callback influence, arbitrary read, arbitrary write, or type confusion. None is demonstrated. * +0 Confidentiality impact. An internal potential out of bounds read does not establish that bytes are returned to userspace, firmware, a device, or another observable interface. * +0 Integrity impact. No concrete memory write beyond an intended destination or protected-state modification is established. * +0 Local unprivileged trigger. The supplied material does not show that an ordinary local user can control the AML operands or load a crafted ACPI table. * +0 Remote reachability. Firmware-mediated AML is not a directly network-reachable interface. * +0 Privilege escalation. No practical LPE chain, authorization bypass, or write primitive is established. * +0 Extra Availability. No additional persistent availability effect beyond a possible immediate kernel fault is shown. * No race penalty was applied. This is arithmetic overflow validation logic, not a timing race. * No host-admin penalty was applied. The available evidence does not positively establish the complete privilege boundary for delivering attacker-controlled AML. 3. Reachability analysis The vulnerable operation is in ACPICA AML evaluation for the Mid opcode. Triggering requires an AML method with Index and Length values whose addition wraps, bypassing the original truncation condition. The likely input sources are firmware-provided DSDT or SSDT tables, dynamically injected ACPI tables, or AML exposed through another kernel ACPI evaluation path. The supplied patch does not show a complete attacker path for an ordinary local user. Loading replacement ACPI tables normally involves privileged mechanisms, but malicious firmware is a distinct threat model and does not itself prove that host-admin privileges are required for every case. HostAdminRequired is therefore UNKNOWN rather than YES. NamespaceScopedPrivilege is UNKNOWN because no namespace-aware complete trigger path is shown. There is no direct network input, no demonstrated attacker-controlled device interface, and no special hardware prerequisite established beyond the system evaluating affected ACPI AML. 4. Primitive and severity interpretation The exact established defect is an integer overflow in Index plus Length during AML Mid opcode truncation validation. If the addition wraps, the original greater-than comparison can fail and an invalid large length can reach memcpy. This is not a UAF, refcount bug, ownership violation, security-boundary bypass, or active-object lifetime issue. The patch establishes a potential invalid read or crash condition caused by unchecked arithmetic. It does not establish that memcpy writes beyond its allocated destination, that adjacent source bytes are observable by an attacker, or that attacker-controlled data reaches a security-sensitive target. The demonstrated practical consequence is best treated as possible kernel crash or DoS during evaluation of malformed AML. Limited confidentiality impact is a defensible paranoid concern only if surrounding ACPICA result handling can expose the copied result, but that disclosure path is not visible in the supplied patch. PrimitiveClass is CLASS_C because the currently demonstrated behavior is invalid-state and crash-capable behavior without an independently useful corruption primitive. ImportantCandidate is NO because there is no controlled write, active lifetime corruption, security-boundary bypass, disclosure path, or practical LPE mechanism. AutoDowngradeAllowed is YES because the unresolved concern is suitable for ordinary manual triage and does not contain an established Important-preserving primitive. 5. One-sentence report phrase An integer overflow in the ACPICA AML Mid opcode can bypass length truncation and pass an invalid size to memcpy, potentially causing a kernel crash while evaluating malformed or malicious firmware AML. 6. Manual review recommendation MANUAL CHECK RECOMMENDED The patch prevents an overflow-derived invalid memcpy length in kernel AML processing. Review the full ACPICA Mid opcode allocation and copy path to determine whether the destination size is independently bounded and whether copied bytes can become externally observable. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) [ Upstream Commit: d0d89f2e16a874e0f8fb17045da293e8bedf8b21 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d0d89f2e16a874e0f8fb17045da293e8bedf8b21 Changed files: drivers/acpi/acpica/exoparg3.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=d0d89f2e16a874e0f8fb17045da293e8bedf8b21 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97451 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97451 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: 2 Paranoid ActionableScore: 3 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).