From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-92493][LOW] cpufreq: amd-pstate-ut: Skip tests when amd-pstate driver is not active [ Upstream Date: Thu, 17 Sep 2026 19:24:36 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-92493 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: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 List-Id: CVE: CVE-2026-92493 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: cpufreq: amd-pstate-ut: Skip tests when amd-pstate driver is not active [ Upstream Commit: baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-92493 Analysis date: Thu, 17 Sep 2026 19:24:36 -0400 ActionableScore: 0 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-2026-92493 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-92493 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-2026-92493 LOW https://www.kernelcve.org/list/?q=CVE-2026-92493 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';**CWE-476;CWE-754;CWE-703;BEST CVSS score: '4.4';DESCR 'A NULL pointer dereference can occur in amd_pstate_ut during module initialization because the test module runs amd pstate self tests even when the amd pstate driver is not active or the platform is not AMD. Loading amd_pstate_ut on an Intel platform can reach amd_pstate_ut_check_perf with missing driver state and crash the kernel. For the CVSS the PR:H is selected because reliable triggering normally requires administrative ability to load this kernel test module through modprobe or init_module. The issue is not network reachable and does not provide a useful read or write primitive beyond a crash. Impact is denial of service via kernel Oops or panic only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) YES DANGER NULLPTR HARDWARE DEBUGFS LINUS TEST DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_GUESSCVSS_AND_CIANNH YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=YES NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: -1 * Conservative score: 0 * Raw paranoid score: -1 * Paranoid score: 0 * Applied conservative floor/cap: minimum score clamp -1 -> 0 * Applied paranoid floor/cap: minimum score clamp -1 -> 0 * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Reliable kernel crash / strong DoS. The supplied trace shows a NULL pointer dereference in amd_pstate_ut_check_perf during amd_pstate_ut module initialization. * -2 Host-admin-equivalent privilege required. The demonstrated trigger is modprobe amd_pstate_ut / init_module, which normally requires host root or CAP_SYS_MODULE. * 0 No Real UAF. The patch prevents tests from running when amd-pstate is undefined or disabled, but no stale lifetime or post-free object use is established. * 0 No controlled reclaim, arbitrary write, OOB access, refcount corruption, callback control, or privilege-escalation primitive is demonstrated. * 0 No C/I impact awarded. The evidence supports crash-only behavior. * 0 No remote reachability. The trigger is local module loading, not packet or network input. * 0 No repeated release/refcount signal. There is no first release, surviving dangling reference, or second lifetime-mutating operation. * 0 No extra availability point. The same kernel Oops/panic is already counted as the single DoS signal. 3. Reachability analysis The complete trigger requires loading the amd_pstate_ut kernel test module. That operation is performed through modprobe or init_module and is host-admin-equivalent on normal systems. The crash is observed on a non-AMD or inactive amd-pstate environment because the test module runs amd-pstate self tests without first checking that the amd-pstate driver is active. No namespace-scoped path is established, and no ordinary unprivileged trigger is shown. There is no network path and no race requirement. The platform condition is specific but not scored separately because the host-admin module-loading requirement already dominates the practical risk. 4. Primitive and severity interpretation The exact primitive is a NULL pointer dereference caused by running amd_pstate_ut tests when required amd-pstate driver state is unavailable. This is Class C crash/DoS behavior, not memory corruption with exploitation leverage. The stale-object and repeated-refcount rules do not apply. Demonstrated consequence is kernel Oops or panic during module initialization. Speculative consequences such as privilege escalation are not supported by the patch or supplied context. ImportantCandidate=NO because the issue is host-admin-triggered, crash-only, and lacks a useful corruption or boundary-bypass primitive. AutoDowngradeAllowed=YES because no unresolved Important-grade primitive would be lost by treating it as ordinary low-actionability triage. 5. One-sentence report phrase A host administrator loading amd_pstate_ut on a non AMD or inactive amd pstate platform can trigger a NULL pointer dereference during module initialization, causing a local kernel crash only. 6. Manual review recommendation NO MANUAL CHECK NEEDED Reason: the issue is a host-admin-triggered test-module NULL dereference with no UAF, no C/I primitive, no network reachability, and no privilege-escalation evidence. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: cpufreq: amd-pstate-ut: Skip tests when amd-pstate driver is not active [ Upstream Commit: baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 Changed files: drivers/cpufreq/amd-pstate-ut.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=baf5a7fd3f3e2f4297b42b249f4f4f63214f44c0 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-92493 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-92493 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: Not available The Best / paranoid CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.4 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: 0 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).