From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98407][MODERATE 7.0] wifi: rsi: fix heap OOB write on key removal Date: Wed, 14 Oct 2026 23:19:24 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98407 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: b79e2f6585c014c42384f4caa7a37b3e5d26179c List-Id: CVE: CVE-2026-98407 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: wifi: rsi: fix heap OOB write on key removal Commit: b79e2f6585c014c42384f4caa7a37b3e5d26179c Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b79e2f6585c014c42384f4caa7a37b3e5d26179c Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98407 Analysis date: Wed, 14 Oct 2026 23:19:24 -0400 ActionableScore: 5 ActionableScore lower bound: 3 Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98407 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98407 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 7.0 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-2026-98407 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98407 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=1 LEGACY=MODERATE_KPANIC RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both MODERATE_KPANIC) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H';*CWE-787;CWE-122;CWE-119;Other CVSS 'AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '8.8';DESCR 'A heap out-of-bounds write occurs in rsi_hal_load_key() during key removal because pointer arithmetic treats FRAME_DESC_SZ as a number of struct rsi_set_key objects instead of a byte offset. The resulting memset writes 144 zero bytes about 2.4 KB beyond the end of a 160 byte skb data buffer and can corrupt unrelated kernel heap objects. The vulnerable path runs during DISABLE_KEY processing, including disconnects, roaming, and interface teardown. An attacker within Wi-Fi radio range may be able to induce the key removal path through disconnect related wireless events, although practical reliability can depend on management frame protection and network configuration. For the CVSS the PR:N is used because an adjacent attacker does not need an account or privileges on the target when the wireless event can be induced over the radio interface. Impact is at least denial of service through kernel corruption or crash. Privilege escalation or code execution is not proven, but the deterministic kernel heap overwrite creates a plausible confidentiality and integrity risk that requires manual analysis. Automated impact decision path. The original SimpleNet classifier selected IMPORTANT. The primary LLM estimated paranoid CVSS 8.8 and the production ActionableScore returned 4 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 MODERATE_KPANIC 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 has no review artifact for this run. Exact triggered rule markers were DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP. The independent weaker Aegis shadow evaluated CVSS 3.5 and ActionableScore 1 with primitive class CLASS_B and manual review RECOMMENDED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 4) MAYBE REMOTE WRITE OOB NETWORK SKB HARDWARE KPANIC DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=3 PrimitiveClass=CLASS_B RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=YES ManualReview=REQUIRED AutoDowngradeAllowed=NO RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw conservative score: 3 * Conservative score: 3 * Raw paranoid score: 5 * Paranoid score: 5 * No floor or cap was applied. * Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**:: 2. Signal breakdown Conservative signals: * +1 Constrained kernel buffer overwrite. The faulty `memset()` performs a confirmed 144-byte zero write approximately 2.4 KB beyond a 160-byte heap buffer. Payload and offset are fixed, so CLASS_A control is not established. * +1 Reliable kernel crash or strong DoS. Zeroing unrelated heap objects can realistically corrupt active kernel state and cause an Oops or panic. * +1 Firmware-mediated external influence. Key removal occurs during real wireless disconnect and roaming activity, but the RSI device and firmware mediate the external event. * Total: 3. Paranoid signals: * +1 Constrained kernel buffer overwrite. * +1 Reliable kernel crash or strong DoS. * +2 Adjacent network reachability. A radio-adjacent actor may induce disconnect-related processing that reaches `DISABLE_KEY`, subject to association state and management-frame protection. * +1 Weak exploitation concern. The write reaches unrelated heap objects rather than remaining inside a fixed device buffer, and an adjacent actor may influence its timing. The corrupted object and resulting leverage are unresolved. * Total: 5. Not awarded: * No strong corruption +2 because the payload is fixed zeroes, the offset is fixed, and target selection is not demonstrated. * No arbitrary or directed write, controlled reclaim, callback overwrite, information disclosure, or privilege escalation is established. * No separate availability point because it would double-count the same prospective kernel crash. * No hardware rarity penalty. RSI hardware is required, but the supplied evidence does not establish that it is sufficiently rare to justify `-2`. * No timing penalty. The overwrite occurs on every relevant `DISABLE_KEY` callback and is not a race. * B5-R does not apply. No retry-accumulated index, missing retry reset, or later consumption of retry-corrupted descriptors is involved. * B3-PENDING and B4-PENDING do not apply. There is no shared-backing write or authorization decision bypass. 3. Reachability analysis The vulnerable operation requires an RSI wireless device using this driver and a key-removal event after a key has been installed. Disconnects, roaming, and interface teardown invoke the affected `data == NULL` path. A local network-management actor can cause key removal, but the supplied evidence does not establish whether an ordinary user, delegated service, or host administrator controls the complete local operation. Therefore `HostAdminRequired` remains `UNKNOWN`. A Wi-Fi-adjacent attacker may be able to induce disconnect or roaming behavior through radio traffic. Reliability depends on association state, firmware behavior, and protections such as management-frame protection. This supports adjacent reachability for the paranoid score but is not sufficiently complete to mark below-host-admin triggerability as conclusively established. No namespace-scoped complete trigger chain is shown. No race or retry sequence is required. Prior installation of the driver, compatible hardware, and an active wireless connection are environmental prerequisites. 4. Primitive and severity interpretation The exact primitive is a confirmed heap out-of-bounds write of 144 zero bytes beginning roughly 2.4 KB beyond the allocated skb data buffer. It results from structure-scaled pointer arithmetic where a byte offset was intended. This is not a UAF, repeated release, shared-page ownership violation, or authorization bypass. It is a constrained CLASS_B kernel corruption primitive because the payload and offset are fixed and no adjacent victim selection is demonstrated. Nevertheless, the destination lies among unrelated heap objects, so the write is materially stronger than a bounded overwrite confined to a private device buffer. The demonstrated technical consequence is corruption of unrelated kernel heap objects. Kernel crash and DoS are realistic. Code execution, privilege escalation, and confidentiality impact remain speculative because no corrupted object, reclaim strategy, callback, credential field, or arbitrary write is identified. `ImportantCandidate=YES` and `AutoDowngradeAllowed=NO` are appropriate because an actual cross-object kernel heap overwrite exists and its effect on adjacent active objects requires manual exploitation-leverage analysis. The evidence does not justify CLASS_A or a score of 7 or higher. 5. One-sentence report phrase A fixed 144-byte zero write approximately 2.4 KB beyond an RSI key-command heap buffer can corrupt unrelated kernel objects during Wi-Fi key removal, creating an adjacent-triggerable crash risk and an unresolved kernel-corruption primitive. 6. Manual review recommendation MANUAL CHECK REQUIRED The patch establishes a real cross-object heap overwrite, while the affected adjacent object and practical non-crash exploitation leverage remain unresolved. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: rsi: fix heap OOB write on key removal Commit: b79e2f6585c014c42384f4caa7a37b3e5d26179c Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b79e2f6585c014c42384f4caa7a37b3e5d26179c Commit description: When a key is removed (data == NULL), rsi_hal_load_key() runs: memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ); set_key is a struct rsi_set_key *, so the subscript is scaled by sizeof(struct rsi_set_key) (160 bytes): &set_key[FRAME_DESC_SZ] is skb->data + 2560, and the memset writes 144 zero bytes starting 2.4KB past the end of the 160-byte skb data buffer, corrupting unrelated heap objects. The intended byte offset would have been (u8 *)set_key + FRAME_DESC_SZ. The write fires on every DISABLE_KEY callback, so plain disconnects, roams and interface teardowns trigger it on real networks. The memset is redundant: the whole buffer is zeroed right after allocation, so the frame sent to the device is byte-identical without it. Drop the else branch; normal operation is unaffected. Discovered by Atuin - Automated Vulnerability Discovery Engine. Fixes: dad0d04 ("rsi: Add RS9113 wireless driver") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Tianchu Chen Link: https://patch.msgid.link/90bb2b07007942064c04aa3729cedd9eb1e930b1@linux.dev Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman Changed files: drivers/net/wireless/rsi/rsi_91x_mgmt.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=b79e2f6585c014c42384f4caa7a37b3e5d26179c ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98407 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98407 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:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 8.8 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: 3 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: MODERATE KPANIC detected for this report: YES Published priority for this report (same as in Subject): MODERATE 7.0 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).