From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97410][MODERATE REGULAR] netconsole: take target_cleanup_list_lock in drop_netconsole_target() [ Upstream Date: Thu, 24 Sep 2026 19:37:27 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97410 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: 2 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 84592ee22f7d1583ce33aa733411ff36c7a1c44c List-Id: CVE: CVE-2026-97410 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: netconsole: take target_cleanup_list_lock in drop_netconsole_target() [ Upstream Commit: 84592ee22f7d1583ce33aa733411ff36c7a1c44c Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=84592ee22f7d1583ce33aa733411ff36c7a1c44c Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97410 Analysis date: Thu, 24 Sep 2026 19:37:27 -0400 ActionableScore: 2 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-2026-97410 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97410 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-97410 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97410 CHECK WITH IMPACT FROM ORIG NN LOW 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:L/A:H';CWE-362;CWE-667;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.2';DESCR 'A race condition in dynamic netconsole target removal can corrupt a kernel linked list when a configfs target is removed while the cleanup worker traverses target_cleanup_list after the underlying network interface has been unregistered. Concurrent list_del and list traversal use disjoint locks for the same list node. This can cause kernel list corruption and at least a local denial of service through a kernel crash or stuck cleanup path. For the CVSS the PR:H rating is used because creating and removing dynamic netconsole configfs targets normally requires administrative control over host configuration. The issue is not directly network reachable. For the paranoid score limited confidentiality and integrity impact is considered because kernel list corruption is present. A full privilege escalation primitive is not demonstrated by the patch and requires manual review.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES LOCK SIMPLEFIX RACE NETWORK DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=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: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Concrete kernel list corruption candidate. The patch establishes concurrent list_del and cleanup-list traversal under disjoint locks while operating on the same list node. * +1 Realistic local DoS. Corruption of an actively traversed kernel linked list can cause a kernel fault, hang, or stuck cleanup path. * +0 Remote reachability. Netconsole is networking related, but the vulnerable operation is configfs target deletion combined with local netdevice unregister processing. Remote packet traffic does not directly reach this path. * +0 RealUAF. No object free, post-free dereference, second put, refcount mutation, or stale post-lifetime object use is established. * +0 Controlled reclaim or object replacement. The patch does not show attacker-controlled replacement of the netconsole target or list node after corruption. * +0 Arbitrary or directed write. Concurrent list manipulation can corrupt list links, but no attacker-selected destination or payload is demonstrated. * +0 Confidentiality and integrity. No disclosure, protected-object modification, credential impact, or authorization bypass is established. * +0 Strong exploitation leverage. The demonstrated mechanism is an invalid concurrent list operation in cleanup processing, not a controlled active-object corruption primitive. * +0 Privilege penalty. Host-admin-equivalent privilege is plausible for dynamic netconsole configfs administration, but the supplied evidence does not positively establish the complete privilege boundary. No unsupported negative penalty is applied. * No race penalty. The issue is a race, but the supplied evidence does not establish an unusually narrow, one-shot, or externally uncontrollable timing condition. 3. Reachability analysis The trigger requires removal of a dynamic netconsole configfs target while the associated network interface is being unregistered and the cleanup worker is traversing target_cleanup_list. The relevant attacker is a local actor able to remove the affected netconsole configfs target and influence or coincide with netdevice unregister processing. Dynamic netconsole configuration is commonly administrative, but the supplied patch does not establish whether all required operations require host-root-equivalent authority, can be delegated to a service account, or can be completed from an attacker-controlled namespace. The complete trigger is not shown to be namespace-scoped. Configfs target management, netconsole target state, and the underlying interface lifecycle may involve host-global state. Therefore NamespaceScopedPrivilege is UNKNOWN. No special hardware, boot parameter, firmware input, or direct network packet prerequisite is established. The vulnerable sequence is local control-plane activity and cleanup processing. 4. Primitive and severity interpretation The exact primitive is a concurrent linked-list unlink and traversal race. The configfs removal path performs list_del while holding target_list_lock, whereas the cleanup worker can traverse the same target node on target_cleanup_list while holding target_cleanup_list_lock. The disjoint locking permits list-link corruption. This is not a RealUAF based on supplied evidence. The patch does not show that the netconsole target is freed while a stale reference remains in use. It also does not establish a repeated release, refcount decrement, double free, controlled replacement, callback dispatch from corrupted data, arbitrary write, or information disclosure. The affected list node belongs to an active netconsole target object, but the demonstrated stale operation is limited to cleanup and unregister-related list management. The useful attacker-controlled primitive after excluding a possible crash is unresolved and not established. This supports CLASS_C rather than CLASS_B or CLASS_A. The demonstrated consequence is local denial of service through possible kernel list corruption, kernel fault, or a stuck cleanup path. Privilege escalation, confidentiality impact, and integrity impact remain speculative and are not scored. ImportantCandidate is NO because the patch does not establish meaningful exploitation leverage beyond crash or cleanup disruption. AutoDowngradeAllowed is YES because no concrete UAF, post-free mutation, controlled corruption, or security-boundary bypass remains unresolved. 5. One-sentence report phrase A race between dynamic netconsole configfs target removal and cleanup-list traversal can corrupt a kernel linked list and cause a local denial of service through a kernel crash or stuck cleanup path. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Confirm the configfs permission model and whether a non-host-admin service account or delegated namespace actor can perform both dynamic target removal and the required netdevice lifecycle operations. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: netconsole: take target_cleanup_list_lock in drop_netconsole_target() [ Upstream Commit: 84592ee22f7d1583ce33aa733411ff36c7a1c44c Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=84592ee22f7d1583ce33aa733411ff36c7a1c44c Changed files: drivers/net/netconsole.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=84592ee22f7d1583ce33aa733411ff36c7a1c44c ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97410 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97410 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:L/A:H The Best / paranoid CVSS score: 5.2 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: 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: 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).