From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98889][IMPORTANT] wifi: iwlwifi: mvm: fix sched scan IE sizing [ Upstream Date: Tue, 27 Oct 2026 03:16:58 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98889 X-AL-KERNEL-Priority: IMPORTANT X-AL-KERNEL-Severity: IMPORTANT X-AL-KERNEL-Base-Severity: IMPORTANT X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: f2268060e99f94314b9988dfa17393c2694fa9b2 List-Id: CVE: CVE-2026-98889 Priority: IMPORTANT AL-KERNEL base severity: IMPORTANT KPANIC flag: NO Patch: wifi: iwlwifi: mvm: fix sched scan IE sizing [ Upstream Commit: f2268060e99f94314b9988dfa17393c2694fa9b2 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f2268060e99f94314b9988dfa17393c2694fa9b2 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98889 Analysis date: Tue, 27 Oct 2026 03:16:58 -0400 ActionableScore: 5 ActionableScore lower bound: unknown Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review Manual review required: YES Summary: Authorized scheduled-scan IE input can overflow an iwlwifi fixed probe-request buffer before size validation, producing a confirmed kernel heap overwrite with unknown post-corruption leverage. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98889 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98889 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: IMPORTANT Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-98889 IMPORTANT https://www.kernelcve.org/list/?q=CVE-2026-98889 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=1 LEGACY=IMPORTANT RESULT=DIFF INDEPENDENT_LEGACY=IMPORTANT INDEPENDENT_RESULT=DIFF TEMP_KPANIC_MERGE=IMPORTANT_WINS_DISAGREEMENT PRE_MERGE_LEGACY=IMPORTANT (final Legacy and Aegis differ; FINAL: IMPORTANT, Aegis: MODERATE_KPANIC) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-787;*CWE-20;CWE-131;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'A scheduled scan request can cause an out of bounds write because iwl_mvm_build_scan_probe copied user supplied IEs and driver inserted DS or TPC bytes into the fixed preq buffer before iwl_mvm_scan_fits rejected the complete size. The demonstrated primitive is a kernel memory overwrite, although the available diff does not establish the exact adjacent object or a reliable privilege escalation technique. For the CVSS the PR:L value reflects that reliable triggering requires a local process authorized to start scheduled WiFi scans, commonly through CAP_NET_ADMIN or a trusted WiFi service, rather than remote radio traffic alone. Base impact is limited confidentiality and integrity with high availability, while the paranoid score uses high impact because corruption adjacent to a fixed kernel buffer may permit a crash or privilege escalation. Automated impact decision path. The original SimpleNet classifier selected IMPORTANT. The primary LLM estimated paranoid CVSS 7.8 and the production ActionableScore returned 5 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were KP and FD specialist checks stage IMPORTANT to IMPORTANT because a specific evidence based protection or manual review veto was applied. final reconciliation stage IMPORTANT to IMPORTANT because KP specialist did not establish a qualifying panic. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist produced a review artifact and its decision was processed by the applicable downgrade and preservation rules. Exact triggered rule markers were V59_LEGACY_CLASSA_KP_VETO and MANUAL_REVIEW_REQUIRED and V42_LEGACY_CLASSA_FD_VETO and MANUAL_REVIEW_REQUIRED and TEMP_KPANIC_MERGE_IMPORTANT_WINS and KPANIC_UNSUPPORTED_REMOVED. The independent weaker Aegis shadow evaluated CVSS 2.3 and ActionableScore 1 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is IMPORTANT.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) MAYBE REMOTE SIMPLEFIX NETWORK LINUS V59_LEGACY_CLASSA_KP_VETO MANUAL_REVIEW_REQUIRED V42_LEGACY_CLASSA_FD_VETO MANUAL_REVIEW_REQUIRED TEMP_KPANIC_MERGE_IMPORTANT_WINS KPANIC_UNSUPPORTED_REMOVED - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 PrimitiveClass=CLASS_A RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=YES ManualReview=REQUIRED AutoDowngradeAllowed=NO RequiresHostUID0=NO AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 3. * Conservative score: 5. Applied the strong-corruption/manual-review safety floor: 3 -> 5. * Raw paranoid score: 3. * Paranoid score: 5. No additional speculative leverage awarded; same safety floor applies. * Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**:: 2. Signal breakdown * +2 — Confirmed attacker-influenced heap OOB write: oversized scheduled-scan IEs were copied into the fixed probe-request buffer before complete-size validation. * +1 — Kernel crash/strong DoS is plausible from corruption beyond the fixed buffer. * +1 — Intel Wi-Fi scheduled scanning is a broadly deployed, operationally exercised path. * -1 — Trigger requires reduced/delegated scan authority, described as CAP_NET_ADMIN or an authorized Wi-Fi service, rather than ordinary unprivileged access. * No arbitrary target, adjacent victim, controlled reclaim, callback overwrite, disclosure, or LPE is shown. * No extra availability point: it would duplicate the corruption-induced crash. * NEW52 B5-R does not apply: no retry-accumulated index, missing retry reset, or later consumption of retry-corrupted structured state is shown. * B4-PENDING does not apply because no authorization decision is bypassed. 3. Reachability analysis A local process authorized to initiate scheduled Wi-Fi scans can supply the IE data and exercise the vulnerable copy. The supplied evidence supports reduced privilege below full host-administrator powers, but does not establish that the complete operation works using attacker-obtainable namespace-scoped capabilities. No remote-radio trigger is shown. Intel Wi-Fi hardware is required, but it is common hardware and does not justify a rare-hardware penalty. No race or retry sequence is required. 4. Primitive and severity reading The primitive is a direct, attacker-influenced overwrite beyond a fixed kernel probe-request buffer caused by validation occurring after the copy. This is CLASS_A even though the adjacent allocation layout and useful victim are unknown. The write itself is proven; reliable exploitation, confidentiality impact, integrity impact against protected state, and privilege escalation are unproven. ImportantCandidate is YES because a real heap overwrite cannot safely be reduced to crash-only treatment. Auto-downgrade is disallowed pending allocator-layout and overwrite-reach analysis. 5. One-sentence report phrase Authorized scheduled-scan IE input can overflow an iwlwifi fixed probe-request buffer before size validation, producing a confirmed kernel heap overwrite with unknown post-corruption leverage. 6. Manual review advice MANUAL CHECK REQUIRED Determine overwrite extent, allocation layout, reachable adjacent objects, and whether delegated Wi-Fi services provide practical triggering. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: iwlwifi: mvm: fix sched scan IE sizing [ Upstream Commit: f2268060e99f94314b9988dfa17393c2694fa9b2 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f2268060e99f94314b9988dfa17393c2694fa9b2 Changed files: drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c drivers/net/wireless/intel/iwlwifi/mvm/scan.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=f2268060e99f94314b9988dfa17393c2694fa9b2 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98889 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98889 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:L/I:L/A:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.8 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: 5 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: IMPORTANT KPANIC detected for this report: NO Published priority for this report (same as in Subject): IMPORTANT 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).