From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-63998][LOW] ethtool: module: call ethnl_ops_complete() on module flash errors [ Upstream Date: Sun, 19 Jul 2026 14:29:29 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-63998 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: 1 X-AL-KERNEL-ActionableScore-Lower: 0 X-AL-KERNEL-Commit: d9defbf8b62bde89e206d74c2a2b445b9ed66108 List-Id: CVE: CVE-2026-63998 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ethtool: module: call ethnl_ops_complete() on module flash errors [ Upstream Commit: d9defbf8b62bde89e206d74c2a2b445b9ed66108 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d9defbf8b62bde89e206d74c2a2b445b9ed66108 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-63998 Analysis date: Sun, 19 Jul 2026 14:29:29 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: An ethtool module firmware flash validation error could skip `ethnl_ops_complete()` after `ethnl_ops_begin()`, leaving device-management state inconsistent and causing local administrative DoS or operation degradation. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-63998 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-63998 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-2026-63998 LOW 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:L';CWE-703;CWE-459;*CWE-772;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '3.3';DESCR 'An error path in ethtool module firmware flash handling skipped ethnl_ops_complete after ethnl_ops_begin had already succeeded. If validation of the module flash request fails, the driver specific begin operation may remain unmatched, which can leave driver state, runtime references, or operation serialization in an inconsistent state. For the CVSS the PR:L paranoid interpretation is only relevant where CAP_NET_ADMIN or equivalent ethtool control is delegated to a less trusted local user or service. In the typical host configuration PR:H is more realistic because transceiver firmware flashing is an administrative operation. The issue is not network reachable and is triggered through a local netlink control plane request. Impact is denial of service or device management degradation only, with no evidence of memory corruption, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) SKIP CVE-2026-63998 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: 32b4c8b53ee7 YES NO NO unknown MAYBE SIMPLEFIX LINUS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_GUESSCVSS - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Triggered signals: * Privileged device-management state imbalance: +1 `ethnl_ops_begin()` was already called, but the validation error path skipped `ethnl_ops_complete()`. This can leave driver operation state or serialization cleanup incomplete. * Availability impact realistic: +1 The likely effect is local device-management degradation, stuck operation state, or failed later ethtool/module flash operations. No kernel crash is shown. Subtracted signals: * Requires admin/root/CAP_NET_ADMIN in typical deployments: -2 Transceiver module firmware flashing through ethtool netlink is an administrative control-plane operation. * Rare and difficult-to-reach path: -1 The bug requires the module firmware flashing path and specifically a validation failure after `ethnl_ops_begin()`. Not triggered: * No remote/network trigger. * No local unprivileged trigger in typical deployments. * No UAF, OOB, double free, arbitrary write, refcount takeover, or info leak. * No plausible privilege escalation evidence. * No firmware-mediated external influence because the failure occurs in validation before the actual firmware flash operation. Call-site confidence: high. The patch shows the relevant begin/validate/complete control flow directly. ## 3. Reachability analysis The bug is reachable through a local ethtool netlink control-plane request for transceiver module firmware flashing. In normal host deployments this requires administrative privileges such as CAP_NET_ADMIN or equivalent device-management authority. Namespace or container delegation could lower the practical privilege level if a less trusted service or container root is allowed to manage the relevant netdevice, but that is not the default assumption. The path is not packet-triggered and is not remotely reachable through ordinary network traffic. ## 4. Severity interpretation This behaves like an ordinary Moderate or Low-like issue. The realistic impact is an incomplete cleanup path that may cause device-management DoS or inconsistent driver operation state. The patch does not show memory corruption, sensitive data exposure, privilege escalation, or a system-wide crash. The paranoid score is slightly above the conservative score only because begin/complete mismatches in device-management paths can sometimes leave persistent operational state behind. ## 5. One-sentence report phrase An ethtool module firmware flash validation error could skip `ethnl_ops_complete()` after `ethnl_ops_begin()`, leaving device-management state inconsistent and causing local administrative DoS or operation degradation. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED. This can be auto-closed for practical triage unless the affected product delegates ethtool module flashing to less trusted users or services. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ethtool: module: call ethnl_ops_complete() on module flash errors [ Upstream Commit: d9defbf8b62bde89e206d74c2a2b445b9ed66108 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d9defbf8b62bde89e206d74c2a2b445b9ed66108 Changed files: net/ethtool/module.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=d9defbf8b62bde89e206d74c2a2b445b9ed66108 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-63998 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-63998 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:H/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:L The Best / paranoid CVSS score: 3.3 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: 0 Paranoid ActionableScore: 1 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).