From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-45982][LOW] ACPICA: Fix NULL pointer dereference in acpi_ev_address_space_dispatch() [ Upstream Date: Wed, 27 May 2026 18:20:24 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-45982 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 2 X-AL-KERNEL-ActionableScore-Lower: 1 X-AL-KERNEL-Commit: 7d99cbe717c1b15a66559215df32312d8cf7e525 List-Id: CVE: CVE-2026-45982 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ACPICA: Fix NULL pointer dereference in acpi_ev_address_space_dispatch() [ Upstream Commit: 7d99cbe717c1b15a66559215df32312d8cf7e525 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7d99cbe717c1b15a66559215df32312d8cf7e525 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45982 Analysis date: Wed, 27 May 2026 18:20:24 -0400 ActionableScore: 2 ActionableScore lower bound: 1 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45982 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45982 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-2026-45982 LOW CHECK 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-476;*CWE-20;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'ACPICA address space dispatch can enter the PCC OpRegion handling path when field_obj is NULL, leading to a NULL pointer dereference in a missed execution path. Triggering depends on ACPI firmware or AML behavior and a PCC platform communication OpRegion, so this is a platform or local trigger rather than a network reachable bug. For the CVSS the PR:L is used only in the paranoid score because an existing ACPI or PCC operation might be reachable through a delegated platform interface, while creating the underlying condition normally requires firmware or administrator level control. Impact is denial of service only through kernel crash. No memory corruption, information disclosure, or privilege escalation primitive is supported by the patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) MAYBE NULLPTR SIMPLEFIX DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=1 1. ActionableScore * Conservative score: 1 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: 2. Signal breakdown * Firmware or platform-mediated influence: +1. The vulnerable path depends on ACPI AML or PCC OpRegion behavior. * Reliable kernel crash / DoS: +1. The bug is a NULL pointer dereference when `field_obj` is missing. * Availability impact realistic: +1. A kernel oops or panic is plausible if the path is reachable. * Rare/platform-specific exposure: -1. This requires PCC OpRegion support and a specific missed ACPICA execution path. * Requires firmware/admin/platform control in typical deployments: -1 to -2. Creating or modifying the underlying ACPI table or firmware condition is not normally available to unprivileged users. * No memory corruption signal. This is NULL dereference only, not UAF, OOB write, arbitrary write, or info leak. 3. Reachability analysis The trigger depends on ACPI firmware or AML invoking `acpi_ev_address_space_dispatch()` for a PCC OpRegion with `field_obj == NULL`. In normal deployments, untrusted users cannot create or modify ACPI tables. A local user might only trigger an already-existing platform path if some ACPI/PCC method is exposed through sysfs, device controls, or platform-specific interfaces. It is not network reachable. 4. Severity interpretation This behaves like a platform-specific DoS issue. The realistic impact is kernel crash or ACPI subsystem failure. There is no supported evidence of confidentiality impact, integrity impact, privilege escalation, or exploitable memory corruption. 5. One-sentence report phrase ACPICA can dereference a NULL `field_obj` in the PCC OpRegion dispatch path, causing a platform-dependent local or firmware-triggered denial of service. 6. Manual review recommendation NO MANUAL CHECK NEEDED. This is a NULL pointer dereference in a platform firmware-driven path with no demonstrated memory corruption, privilege escalation, or remote reachability. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ACPICA: Fix NULL pointer dereference in acpi_ev_address_space_dispatch() [ Upstream Commit: 7d99cbe717c1b15a66559215df32312d8cf7e525 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7d99cbe717c1b15a66559215df32312d8cf7e525 Changed files: drivers/acpi/acpica/evregion.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=7d99cbe717c1b15a66559215df32312d8cf7e525 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45982 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45982 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: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: 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 alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).