From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98827][IMPORTANT] wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE [ Upstream Date: Sat, 24 Oct 2026 08:04:22 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98827 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: c18882768a0fe253c70986c5fe66d9241570fbc4 List-Id: CVE: CVE-2026-98827 Priority: IMPORTANT AL-KERNEL base severity: IMPORTANT KPANIC flag: NO Patch: wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE [ Upstream Commit: c18882768a0fe253c70986c5fe66d9241570fbc4 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c18882768a0fe253c70986c5fe66d9241570fbc4 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98827 Analysis date: Sat, 24 Oct 2026 08:04:22 -0400 ActionableScore: 5 ActionableScore lower bound: unknown Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review Manual review required: YES Summary: Local traffic through a configured ath9k_htc interface can drive attacker-influenced packet data up to 13,152 bytes beyond a fixed heap transmit buffer. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98827 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98827 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-2026-98827 IMPORTANT https://www.kernelcve.org/list/?q=CVE-2026-98827 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 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-122;*CWE-20;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'The ath9k_htc USB transmit path can copy multiple large skb records into a fixed 32768 byte heap buffer while limiting aggregation only by frame count. With MTU 2304 the loop can write up to 13152 bytes beyond tx_buf buf using packet data controlled by the traffic source. For the CVSS the PR:L value is selected because reliable triggering normally requires a local unprivileged process that can generate sustained traffic through an already configured ath9k_htc interface. The concrete primitive is a kernel heap OOB write and the immediate impact includes kernel crash. Corruption of adjacent heap objects may also permit confidentiality or integrity impact and possible privilege escalation, although reliable exploitation beyond denial of service is not demonstrated. Direct remote reachability from an unauthenticated wireless peer is not established by the patch. 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 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 TEMP_KPANIC_MERGE_IMPORTANT_WINS and KPANIC_UNSUPPORTED_REMOVED. The independent weaker Aegis shadow evaluated CVSS 4.3 and ActionableScore 2 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 USB UAF NETWORK SKB HARDWARE TEMP_KPANIC_MERGE_IMPORTANT_WINS KPANIC_UNSUPPORTED_REMOVED - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 PrimitiveClass=CLASS_A RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=NO ImportantCandidate=YES ManualReview=REQUIRED AutoDowngradeAllowed=NO RequiresHostUID0=NO AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 5. * Conservative score: 5; no floor or cap applied. * Raw paranoid score: 5. * Paranoid score: 5; stronger consequences require unsupported adjacent-object or exploit assumptions. * Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**:: 2. Signal breakdown * +2 — Strong corruption primitive: cumulative copies of attacker-influenced skb data can write up to 13,152 bytes beyond a 32,768-byte heap buffer. * +1 — Local unprivileged trigger: supplied evidence grounds sustained traffic generation through an already configured ath9k_htc interface without host-admin privilege. * +1 — Reliable kernel crash/strong DoS is plausible from a large heap overwrite. * +1 — Exploit-leverage concern: the overwrite is large and its bytes derive from packet contents, although the adjacent target is allocator-dependent. * No extra availability point: it would duplicate the same crash. * No C/I or LPE points: no adjacent victim, directed target, disclosure, controlled reclaim, or completed escalation is shown. * No remote point: unauthenticated wireless-peer reachability is not established. * B5-R does not apply: offset accumulation occurs within one aggregation batch, not across retries or re-entry. The independently proven OOB write remains CLASS_A. 3. Reachability analysis A normal local process can generate large traffic through a configured ath9k_htc USB interface. Initial hardware attachment and interface configuration require prior administrative/device setup, but the evidenced later traffic trigger does not require UID 0 or an attacker-held capability. No namespace-scoped privilege is involved. Specific ath9k_htc hardware is required, but the evidence does not establish that it is sufficiently rare or physical-attacker-only to justify a hardware penalty. No timing race is required. 4. Primitive and severity reading The primitive is a direct, attacker-influenced heap OOB write from repeated `memcpy()` operations into a fixed transmit aggregation buffer. It is neither a UAF nor stale-storage access. The subsequent URB submission consumes the corrupted aggregation buffer, but no specific corrupted adjacent kernel object is identified. The shown effects support crash and material heap corruption; arbitrary write, confidentiality loss, integrity compromise, and LPE remain unproven. The real controlled-data OOB write makes this CLASS_A, requires Important review, and precludes automatic downgrade. 5. One-sentence report phrase Local traffic through a configured ath9k_htc interface can drive attacker-influenced packet data up to 13,152 bytes beyond a fixed heap transmit buffer. 6. Manual review advice MANUAL CHECK REQUIRED The substantial attacker-influenced heap overwrite is proven, while adjacent-object leverage and practical exploitation remain unresolved. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE [ Upstream Commit: c18882768a0fe253c70986c5fe66d9241570fbc4 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c18882768a0fe253c70986c5fe66d9241570fbc4 Changed files: drivers/net/wireless/ath/ath9k/hif_usb.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=c18882768a0fe253c70986c5fe66d9241570fbc4 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98827 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98827 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).