From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80967][LOW] ALSA: pcxhr: initialize mutexes before requesting threaded IRQ Date: Fri, 11 Sep 2026 16:23:38 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80967 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: c069b3cfd753d6688ea0271c43553631ab38ce10 List-Id: CVE: CVE-2026-80967 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ALSA: pcxhr: initialize mutexes before requesting threaded IRQ Commit: c069b3cfd753d6688ea0271c43553631ab38ce10 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c069b3cfd753d6688ea0271c43553631ab38ce10 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80967 Analysis date: Fri, 11 Sep 2026 16:23:38 -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-2026-80967 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80967 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-2026-80967 LOW https://www.kernelcve.org/list/?q=CVE-2026-80967 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-362;CWE-665;CWE-667;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.4';DESCR 'pcxhr_probe registers a threaded IRQ before mgr lock, mgr msg_lock, and mgr setup_mutex are initialized. An early interrupt during probe can enter pcxhr_threaded_irq() and use an uninitialized mutex, which can result in a kernel warning, deadlock, or crash. For the CVSS the PR:H is selected because reliable triggering normally requires administrative control over driver probing, module loading, PCI device binding, or equivalent local hardware management. The issue is not network reachable and is tied to local PCI device probe timing. Impact is denial of service only, with no evident information disclosure or privilege escalation primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) YES INIT SIMPLEFIX HARDWARE LINUS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_GUESSCVSS_AND_CIANNH NO 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: -2 * Conservative score: 0 * Raw paranoid score: -1 * Paranoid score: 0 * Applied conservative floor/cap: lower bound -2 -> 0 * Applied paranoid floor/cap: lower bound -1 -> 0 * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown Positive signals: * +1 Reliable kernel crash / strong DoS: an early threaded IRQ may use uninitialized mutex state during probe, causing warning, deadlock, or kernel crash. Negative signals: * -2 Host-admin-equivalent requirement: reliable triggering requires driver probing, module loading, PCI device binding, or equivalent host device-management control. * -1 Conservative timing limitation: the vulnerable window is an early probe-time interrupt ordering issue. Paranoid adjustment: * The paranoid score withholds the timing penalty because a real device may generate an early interrupt naturally once the IRQ is registered. Important non-awarded signals: * No UAF or stale post-lifetime object use is established. * No repeated release, put, free, or refcount mutation is established. * No controlled reclaim, arbitrary write, callback control, or information disclosure is demonstrated. * No remote reachability is established. * No extra Availability point is awarded because the same crash/deadlock is already counted once. * C/I impact is not awarded because the patch supports invalid synchronization state and DoS only. 3. Reachability analysis The trigger is local and tied to PCI driver probe timing for the ALSA pcxhr driver. A normal unprivileged user is not shown to be able to force the complete vulnerable sequence. Reliable triggering normally requires host-admin-equivalent control over module loading, PCI bind/unbind, driver probing, or comparable hardware-management operations. The issue is not namespace scoped. No network path is involved. Prior device presence is required, but no separate rare-hardware penalty was added beyond the host-admin and probe-timing limitations. The race window is narrow and occurs between request_threaded_irq() and mutex initialization. 4. Primitive and severity interpretation The exact primitive is use of uninitialized mutex state by pcxhr_threaded_irq() if an interrupt arrives after request_threaded_irq() but before mgr->lock, mgr->msg_lock, and mgr->setup_mutex are initialized. This is not an active structured UAF and not fixed stale storage. It is a probe-time initialization-order race with demonstrated consequence limited to warning, deadlock, or crash. PrimitiveClass is CLASS_C. ImportantCandidate is NO because there is no memory-corruption, lifetime, ownership, authorization, or boundary-bypass primitive. AutoDowngradeAllowed is YES because this is host-admin-gated, local, probe-timing dependent, and DoS-only. 5. One-sentence report phrase ALSA pcxhr registers a threaded IRQ before initializing manager mutexes, allowing an early probe-time interrupt to use uninitialized synchronization state and potentially cause a local host crash or deadlock. 6. Manual review recommendation NO MANUAL CHECK NEEDED Reason: the issue is local, host-admin-gated, probe-timing dependent, and no UAF, repeated lifetime mutation, controlled corruption, information disclosure, or privilege-escalation primitive is established. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ALSA: pcxhr: initialize mutexes before requesting threaded IRQ Commit: c069b3cfd753d6688ea0271c43553631ab38ce10 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c069b3cfd753d6688ea0271c43553631ab38ce10 Commit description: pcxhr_probe() requests pcxhr_threaded_irq() before initializing mgr->lock, even though the threaded handler takes that mutex. Initialize the manager locks before request_threaded_irq() so an early interrupt cannot run against uninitialized mutex state during probe. Fixes: 9bef72b ("ALSA: pcxhr: Use nonatomic PCM ops") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao Link: https://patch.msgid.link/20260818144717.2269918-1-runyu.xiao@seu.edu.cn Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman Changed files: sound/pci/pcxhr/pcxhr.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=c069b3cfd753d6688ea0271c43553631ab38ce10 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80967 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80967 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: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).