From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64526][MODERATE REGULAR] ethtool: tsconfig: fix missing ethnl_ops_complete() [ Upstream Date: Sat, 25 Jul 2026 08:34:33 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64526 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: 3 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 List-Id: CVE: CVE-2026-64526 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ethtool: tsconfig: fix missing ethnl_ops_complete() [ Upstream Commit: d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64526 Analysis date: Sat, 25 Jul 2026 08:34:33 -0400 ActionableScore: 3 ActionableScore lower bound: 2 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A local ethtool tsconfig error path can return ENODEV after ethnl_ops_begin without calling ethnl_ops_complete, leaving driver operation state unfinished and causing possible local DoS or resource retention, but no memory corruption or privilege escalation primitive is shown. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64526 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64526 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-2026-64526 MODERATE 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:L/UI:N/S:U/C:N/I:N/A:H';*CWE-772;CWE-703;CWE-754;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'ethtool tsconfig_prepare_data can return ENODEV after ethnl_ops_begin without calling ethnl_ops_complete when the device has no PHC index. This breaks the expected begin and complete pairing for ethtool driver operations and may leave driver state or resources unfinished depending on the implementation. For the CVSS the PR:L is used because triggering requires a local process able to issue the ethtool netlink request, not a remote packet path. The issue is not directly network reachable. Impact is denial of service only, mainly through leaked operation state or resource retention in affected drivers. There is no evidence of memory corruption, information disclosure, or privilege escalation from the patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 3) YES SIMPLEFIX LINUS YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 ActionableScoreLower=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 3 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Conservative signals: * Local unprivileged trigger: +1. The path is a local ethtool netlink control/query path rather than a remote packet-processing path. * Availability impact realistic: +1. Missing `ethnl_ops_complete()` can leave driver operation state or resources unfinished after `ethnl_ops_begin()`, plausibly causing local resource retention or device state issues. Paranoid additional signal: * Broad/common subsystem exposure: +1. ethtool/netdev control paths are common, although this specific `tsconfig` path and `phc_index == -1` condition are narrower than core packet receive/transmit paths. Not applied: * Remote reachable: +0. No packet-triggered or network-origin trigger is shown. * Generic memory corruption: +0. The patch shows a missing cleanup/complete call, not UAF, OOB, double-free, type confusion, or arbitrary write. * Privilege escalation plausible: +0. No concrete LPE primitive is present. * Reliable kernel crash / strong DoS: +0. The commit does not show panic, Oops, deadlock, or a reliably reproducible host-wide crash. * Requires admin/CAP penalty: 0 in the main interpretation, because ethtool query paths may be reachable by local users depending on command/policy. If the evaluated product gates this command behind CAP_NET_ADMIN, the score should be lower. ## 3. Reachability analysis The bug is triggered locally through the ethtool tsconfig netlink path when `tsconfig_prepare_data()` calls `ethnl_ops_begin()` and then hits the `ts_info.phc_index == -1` error case. The missing `ethnl_ops_complete()` affects cleanup symmetry for driver operations. This is not remotely reachable through normal network traffic. Namespaces or containers matter only if they expose the relevant ethtool netlink operation to a reduced-privilege user. The path is part of a common networking administration subsystem, but the exact trigger requires a device/driver state where no PHC index is available. Call-site confidence: medium. The patch clearly shows the missing begin/complete pairing, but the exact downstream effect depends on driver-specific `begin` and `complete` implementations. ## 4. Severity interpretation This behaves like an ordinary Moderate or Low-like cleanup/resource-state issue, not an Important-class vulnerability. The realistic impact is local denial of service or degraded device state from skipped completion handling. Theoretical impact beyond DoS is not supported by the patch because there is no demonstrated stale pointer reuse, memory corruption, sensitive object access, or privilege-boundary bypass. The paranoid score only raises the issue to borderline manual-review territory because driver-specific `complete()` callbacks can release resources or restore state, but this remains below Actionable Moderate without evidence of a stronger failure mode. ## 5. One-sentence report phrase A local ethtool tsconfig error path can return ENODEV after ethnl_ops_begin without calling ethnl_ops_complete, leaving driver operation state unfinished and causing possible local DoS or resource retention, but no memory corruption or privilege escalation primitive is shown. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be auto-closed for urgent triage purposes unless the affected product has a known driver where missing `ethnl_ops_complete()` causes a persistent device hang or system-wide resource leak. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ethtool: tsconfig: fix missing ethnl_ops_complete() [ Upstream Commit: d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 Changed files: net/ethtool/tsconfig.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=d02342d9bb4f0ab682f1846a4fbc15dd2955f7e6 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64526 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64526 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:L/PR:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.5 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: 2 Paranoid ActionableScore: 3 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).