From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98317][LOW] neighbour: Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS. [ Upstream Date: Fri, 09 Oct 2026 23:29:10 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98317 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: unknown X-AL-KERNEL-Commit: 982c7f66c04134b77126edbfd8a63ecd6928cfd9 List-Id: CVE: CVE-2026-98317 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: neighbour: Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS. [ Upstream Commit: 982c7f66c04134b77126edbfd8a63ecd6928cfd9 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=982c7f66c04134b77126edbfd8a63ecd6928cfd9 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98317 Analysis date: Fri, 09 Oct 2026 23:29:10 -0400 ActionableScore: 1 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: Missing range validation for the managed neighbour probe interval allows zero or overflowing values to produce immediate delayed-work scheduling, potentially causing excessive CPU and network activity through a privileged control-plane configuration. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98317 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98317 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-2026-98317 LOW https://www.kernelcve.org/list/?q=CVE-2026-98317 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both LOW) 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-20;CWE-681;**CWE-400;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'Missing range validation for NDTPA_INTERVAL_PROBE_TIME_MS allows zero and oversized u64 values to become an invalid probe interval through truncation or integer conversion. A zero or effectively expired delay can cause NTF_MANAGED neighbour entries to be probed much more frequently than intended, potentially increasing CPU usage and network traffic and degrading availability. For the CVSS the PR:L value in the paranoid assessment reflects environments where CAP_NET_ADMIN is delegated to a container or a restricted network management service. Normal host configurations usually require administrative control and support PR:H for the base assessment. The issue is not directly network reachable because an attacker must modify neighbour table parameters through rtnetlink or sysctl. There is no demonstrated UAF, OOB access, information leak, or write primitive, so the supported impact remains denial of service only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) MAYBE REMOTE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 KPANIC_UNSUPPORTED_REMOVED - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 PrimitiveClass=NONE RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO ## 1. ActionableScore * Raw conservative score: 1 * Conservative score: 1 * Raw paranoid score: 1 * Paranoid score: 1 * No floor or cap applied. * Final recommended bucket: **Ordinary Moderate**:: ## 2. Signal breakdown * **+1 Reliable availability degradation:** Missing range validation permits a zero effective interval. Oversized `u64` input can also become zero through truncation, while an overflowing negative `int` can become an already-expired delay after conversion to `unsigned long`. This can cause excessively frequent probing of `NTF_MANAGED` entries and consume CPU or network capacity. * **No memory-corruption points:** The patch establishes invalid numeric conversion and timer scheduling, not a heap OOB access, UAF, stale pointer, arbitrary write, or corrupted descriptor consumption. * **No additional availability point:** Host-wide failure, persistent exhaustion, panic, or an independent availability consequence is not demonstrated. * **No local-unprivileged bonus:** The supplied evidence does not establish that an ordinary user can complete parameter configuration, create the required managed neighbour state, and exercise the vulnerable path. * **No remote-reachability bonus:** Network packets alone do not set this control-plane parameter. * **No privilege penalty:** `CAP_NET_ADMIN` is expected for the setters, but the evidence does not resolve whether the complete trigger requires host-admin-equivalent authority or can be completed in an attacker-created namespace. * **No common-path bonus:** Neighbour processing is common, but the vulnerable behavior specifically depends on invalid configuration of the `NTF_MANAGED` probe interval. * **B5-R does not apply:** There is no confirmed heap or slab OOB write and no later consumption of corrupted structured state. * **B3-PENDING does not apply:** There is no shared-backing or file-backed write. * **B4-PENDING does not apply:** No authorization DENY-to-ALLOW decision is bypassed. * Repeated release, refcount mutation, UAF floors, structured stale-object leverage, controlled reclaim, confidentiality impact, and integrity impact are not applicable. The listed signals total **1** for both assessments. ## 3. Reachability analysis The demonstrated setters are the `rt-neigh` netlink control path and the neighbour sysctl path. Both are privileged configuration interfaces rather than packet-driven data paths. `CAP_NET_ADMIN` is relevant, but the supplied context does not show the exact capability checks or prove that every required stage can be completed in an attacker-created user and network namespace. In particular, the complete trigger also needs suitable `NTF_MANAGED` neighbour entries whose periodic work consumes the invalid interval. Therefore: * ordinary unprivileged reachability is not established; * host-admin-only reachability is not established; * complete namespace-scoped reachability is unresolved; * no direct remote trigger is established; * no special hardware or race timing is required; * prior creation or configuration of managed neighbour state is required. The malformed values are deterministic once access to the setter is available. This is not a race. ## 4. Primitive and severity interpretation The exact defect is missing numeric range validation followed by unsafe narrowing and signed-to-unsigned time conversion. It permits an invalid zero or effectively expired probe interval to reach delayed-work scheduling. This is a logic and availability defect rather than a memory-lifetime or corruption primitive: * active structured UAF: no; * fixed stale storage: no; * repeated release or refcount mutation: no; * authorization bypass: no; * confirmed OOB access: no; * demonstrated consequence: excessive probing and possible CPU or network-load degradation; * speculative consequence: broader denial of service under sustained configurations with many managed entries; * exploitation leverage beyond availability: none established. `PrimitiveClass=NONE` is appropriate. `ImportantCandidate=NO` because the patch provides no corruption, ownership, authorization, or isolation primitive requiring Important-grade preservation. `AutoDowngradeAllowed=YES` because no unresolved security primitive would be discarded. ## 5. One-sentence report phrase Missing range validation for the managed neighbour probe interval allows zero or overflowing values to produce immediate delayed-work scheduling, potentially causing excessive CPU and network activity through a privileged control-plane configuration. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED The issue is a bounded input-validation and availability defect with no demonstrated memory corruption, authorization bypass, remote trigger, or cross-boundary impact. ## 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: neighbour: Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS. [ Upstream Commit: 982c7f66c04134b77126edbfd8a63ecd6928cfd9 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=982c7f66c04134b77126edbfd8a63ecd6928cfd9 Changed files: net/core/neighbour.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=982c7f66c04134b77126edbfd8a63ecd6928cfd9 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98317 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98317 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: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: unknown 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).