From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-93131][MODERATE REGULAR] platform/x86: dell-privacy: Fix race condition [ Upstream Date: Fri, 18 Sep 2026 05:58:00 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-93131 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: 4 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab List-Id: CVE: CVE-2026-93131 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: platform/x86: dell-privacy: Fix race condition [ Upstream Commit: 239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93131 Analysis date: Fri, 18 Sep 2026 05:58:00 -0400 ActionableScore: 4 ActionableScore lower bound: unknown 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-2026-93131 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93131 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-2026-93131 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-93131 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:L/A:H';*CWE-416;CWE-362;CWE-667;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.8';DESCR 'A race in dell_privacy_has_mic_mute can leave a pointer to privacy_wmi_data valid only while list_mutex is held, but the old code released the mutex before reading features_present. If the Dell privacy WMI device is removed at the same time, the object can be freed before the read and the function can perform a use after free dereference. For the CVSS the PR:L is used in the paranoid score because delegated local device management or a constrained service account may be able to trigger driver or device removal paths, while normal systems usually require administrator privileges. The issue is not network reachable and depends on local device or driver lifetime changes. Impact is at least denial of service via kernel crash, with limited confidentiality or integrity impact only as a conservative UAF read assessment.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4) YES LOCK RACE UAF HARDWARE DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 1 * Conservative score: 4 * Raw paranoid score: 2 * Paranoid score: 4 * Final recommended bucket: **Borderline / manual review recommended**:: Applied conservative FLOOR 4: 1 -> 4. Applied paranoid FLOOR 4: 2 -> 4. 2. Signal breakdown Positive signals: * +2 Real UAF / lifetime violation. The commit directly states that `priv` can be freed if `features_present` is accessed after dropping `list_mutex`. * +0 Reliable kernel crash not awarded conservatively. A stale dereference can plausibly crash, but the supplied text does not show an observed panic, Oops, KASAN report, or deterministic crash trace. * +0 Structured stale-object leverage not awarded. The stale use is a read of `features_present`, not a demonstrated callback, pointer traversal, object selection, refcount mutation, or controlled replacement primitive. * +0 Weak LPE not awarded. A generic UAF read is not enough to infer privilege escalation. * +0 Confidentiality or integrity not awarded. No disclosure path, write primitive, controlled reclaim, or protected-object corruption is established. Negative signals: * -1 conservative hard timing / teardown race. The issue appears to require overlap between `dell_privacy_has_mic_mute()` and device or driver lifetime teardown that can free `privacy_wmi_data`. * No host-admin penalty was applied. Host-admin-equivalent privilege is not positively established from the supplied evidence. * No subsystem rarity penalty was applied. Dell WMI privacy support is hardware-specific, but the prompt requires concrete rare or physical-only evidence before subtracting. Paranoid adjustment: * The paranoid score withholds the timing penalty because the patch establishes a real lifetime bug and the complete reachable call path is not visible. No extra exploitation-leverage point is added. Repeated release/refcount checklist: * First release can end lifetime: not shown in the supplied diff. * Exact same reference survives to a second release: no. * Second operation is a real lifetime/refcount mutation: no. * Concrete repeated release/refcount +1 awarded: no. * Paranoid repeated-refcount leverage +1 awarded: no. * FLOOR 5 applied: no. 3. Reachability analysis The vulnerable function reads Dell privacy WMI state and is likely reached through local platform or driver code that queries microphone mute capability. The freeing side is not shown, but the commit says the object can be freed while the mutex is not held, implying a local device or driver lifetime race. Ordinary unprivileged reachability is not established. Host-admin-equivalent privilege is also not positively established because the full call path and teardown path are not included. Therefore `HostAdminRequired=UNKNOWN`. No namespace-scoped privilege is involved in the supplied evidence. This is not network reachable. No prior privileged setup is proven beyond requiring affected Dell WMI privacy hardware or driver support. The race appears tied to local device or driver lifetime changes, and repeatability is unresolved. 4. Primitive and severity interpretation The exact primitive is a use-after-free dereference of `struct privacy_wmi_data *priv`. The old code obtained `priv` under `list_mutex`, released the mutex, and then read `priv->features_present`. If the list entry is removed and freed after unlock, the final read can access freed memory. This is an active structured object, but the stale use shown is shallow: one feature bit read. It is closer to a constrained Class B lifetime bug than to a strong exploitation primitive. There is no demonstrated controlled reclaim, arbitrary read/write, callback use, refcount mutation, or security-boundary bypass. PrimitiveClass is CLASS_B because a real lifetime violation is directly established. ImportantCandidate is NO because the demonstrated primitive is a narrow stale read with no meaningful unresolved exploitation leverage beyond generic UAF concern. AutoDowngradeAllowed is YES because this looks like a constrained local UAF/DoS-risk issue rather than an Important-preserving corruption primitive. Likely operational severity: borderline Moderate. Manual review is still useful because it is a real UAF race in kernel code, but the supplied evidence does not support Strong Important classification. 5. One-sentence report phrase A race in `dell_privacy_has_mic_mute()` can read `privacy_wmi_data.features_present` after the object is freed because the list mutex was released too early, creating a local UAF dereference risk without a demonstrated network vector or privilege escalation primitive. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: real UAF is established, but the visible stale operation is only a shallow field read and no controlled reclaim, repeated lifetime mutation, arbitrary write, disclosure, or security-boundary bypass is shown. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: platform/x86: dell-privacy: Fix race condition [ Upstream Commit: 239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab Changed files: drivers/platform/x86/dell/dell-wmi-privacy.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=239ae86b7c97341f49d2ba32037ee3ddbaf0f1ab ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-93131 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93131 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:L/A:H The Best / paranoid CVSS score: 5.8 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: 4 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).