From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-68311][MODERATE REGULAR] wifi: mt76: mt7925: guard link STA in decap offload [ Upstream Date: Mon, 10 Aug 2026 15:38:46 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-68311 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 4 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: 1e608cae1ba0b4a600b752efa223fd2be376b143 List-Id: CVE: CVE-2026-68311 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: mt76: mt7925: guard link STA in decap offload [ Upstream Commit: 1e608cae1ba0b4a600b752efa223fd2be376b143 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1e608cae1ba0b4a600b752efa223fd2be376b143 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68311 Analysis date: Mon, 10 Aug 2026 15:38:46 -0400 ActionableScore: 4 ActionableScore lower bound: 3 Actionable bucket: Borderline. Manual review recommended / Actionable Moderate candidate Manual review required: YES Summary: A wireless-adjacent NULL pointer dereference in mt76 mt7925 MLO decap offload handling can allow a malicious or controlled AP or peer to crash the kernel when a vif link has no matching station link. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68311 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68311 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 REGULAR 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-2026-68311 MODERATE CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H';**CWE-476;*CWE-20;CWE-754;Other CVSS 'AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H';BEST CVSS score: '6.5';DESCR 'A NULL pointer dereference in the mt76 mt7925 decap offload path can occur because mt7925_sta_set_decap_offload iterates over vif valid_links and assumes that every vif link has a matching station link. In MLO operation mt792x_sta_to_link can return NULL for a link that belongs to the vif but not to the station, and the driver then touches mlink wcid flags. An attacker would need wireless adjacent reachability and a mt7925 MLO setup where link state can be influenced, for example through a malicious or controlled AP or peer. For the CVSS the PR:N is used because no local account on the victim is needed in the paranoid adjacent network interpretation, only reachability to the wireless protocol path. Impact is denial of service via kernel crash. There is no supported evidence of information disclosure or privilege escalation because the primitive is a NULL pointer dereference rather than UAF, OOB write, or arbitrary write.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline. Manual review recommended / Actionable Moderate candidate (with actual score 4) YES REMOTE SIMPLEFIX NETWORK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 ActionableScoreLower=3 ## 1. ActionableScore * Conservative score: 3 * Paranoid score: 4 * Final recommended bucket: **Borderline. Manual review recommended / Actionable Moderate candidate**:: ## 2. Signal breakdown * Remote reachable / network-triggerable: +2 Wireless-adjacent triggering is plausible if an attacker can influence an mt7925 MLO station state through a malicious or controlled AP or peer. This is not Internet-remote AV:N, but it is not a local syscall-only issue either. * Reliable kernel crash / strong DoS: +1 The patch prevents a direct NULL pointer dereference of `mlink->wcid.flags`. If the inconsistent link state is reached, the failure mode is a kernel crash. * Availability impact realistic: +1 in paranoid score only A wireless-adjacent kernel crash is system-wide DoS if reproducible. I count this only in the paranoid score to avoid double-counting the crash in the conservative score. * Rare AND difficult-to-reach subsystem/configuration: -1 Triggering depends on mt7925 hardware, WiFi MLO/link-station state, and a station/vif link mismatch. This is more constrained than a common packet-processing path. * Weak corruption / NULL dereference: +0 This is a NULL pointer dereference, not UAF, OOB write, arbitrary write, type confusion, or refcount takeover. * Privilege escalation plausible: +0 No LPE primitive is supported by the patch. There is no attacker-controlled reclaim, stale callback, writable stale object, or object replacement. ## 3. Reachability analysis The likely trigger is wireless-adjacent rather than local. An attacker would need radio proximity and influence over the WiFi MLO protocol state, for example via a malicious AP, controlled AP, or peer behavior that causes the vif to have a valid link without a matching station link. No local account on the victim is required in the paranoid interpretation, but realistic triggering requires specific mt7925 hardware and MLO operation. Namespaces and containers are not central here because the affected path is in the wireless driver and mac80211 station/link handling rather than a local namespace-exposed API. ## 4. Severity interpretation This behaves like a DoS-focused wireless-adjacent kernel bug, not an Important-class memory corruption issue. The theoretical impact is a kernel crash from a NULL pointer dereference. Realistic exploitation evidence does not support confidentiality impact, integrity impact, or privilege escalation. Because the path is externally influenceable over WiFi and can crash the kernel, it should not be treated as a trivial local-only cleanup fix, but the hardware and MLO constraints keep it below a strong Important candidate. ## 5. One-sentence report phrase A wireless-adjacent NULL pointer dereference in mt76 mt7925 MLO decap offload handling can allow a malicious or controlled AP or peer to crash the kernel when a vif link has no matching station link. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Manual review is required because the issue is potentially wireless-adjacent and causes a kernel crash, but the review should focus on triggerability in real mt7925 MLO deployments rather than privilege escalation. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mt76: mt7925: guard link STA in decap offload [ Upstream Commit: 1e608cae1ba0b4a600b752efa223fd2be376b143 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1e608cae1ba0b4a600b752efa223fd2be376b143 Changed files: drivers/net/wireless/mediatek/mt76/mt7925/main.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=1e608cae1ba0b4a600b752efa223fd2be376b143 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68311 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68311 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:H/PR:N/UI:R/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 6.5 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: 3 Paranoid ActionableScore: 4 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: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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).