From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-90380][MODERATE 7.0] wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete [ Upstream Date: Thu, 17 Sep 2026 18:09:25 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-90380 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: 6 X-AL-KERNEL-ActionableScore-Lower: 5 X-AL-KERNEL-Commit: aaf414bf81ab4b680580871784b0b929818188eb List-Id: CVE: CVE-2026-90380 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete [ Upstream Commit: aaf414bf81ab4b680580871784b0b929818188eb Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aaf414bf81ab4b680580871784b0b929818188eb Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90380 Analysis date: Thu, 17 Sep 2026 18:09:25 -0400 ActionableScore: 6 ActionableScore lower bound: 5 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-2026-90380 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90380 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-2026-90380 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-90380 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-362;*CWE-664;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.5';DESCR 'A use after free can occur in the mt76 mt7925 Wi-Fi receive path because mt76_rx_poll_complete may still observe an rx_status wcid pointer after the related STA has already been removed. This is a race between STA removal and RX completion, and KASAN reports an invalid access in mt76_rx_poll_complete. For the CVSS the PR:N is used because an adjacent Wi-Fi peer or nearby attacker does not need local account privileges on the victim, although reliable triggering depends on wireless state transitions, timing, and affected mt7925 hardware. The attack surface is adjacent network rather than routed Internet reachability, because the trigger is tied to Wi-Fi link layer activity and station lifecycle events. Impact is at least denial of service via kernel crash, and the paranoid score treats the stale pointer as a use after free memory corruption candidate with possible confidentiality and integrity impact that should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 6) YES REMOTE LOCK DANGER RACE UAF NETWORK IPV6 KPANIC KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFDH YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=6 ActionableScoreLower=5 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=NO NamespaceScopedPrivilege=NO ImportantCandidate=YES ManualReview=REQUIRED AutoDowngradeAllowed=NO 1. ActionableScore * Raw conservative score: 5 * Conservative score: 5. No floor or cap changed the score. * Raw paranoid score: 6 * Paranoid score: 6. No floor or cap changed the score. * Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**:: 2. Signal breakdown Conservative signals: * +2 Real UAF / active lifetime violation. The commit directly states a use-after-free in `mt76_rx_poll_complete`, where `rx_status` still holds a `wcid` pointer after the related STA has been removed. * +1 Reliable kernel crash / strong DoS. KASAN reports invalid access in `mt76_rx_poll_complete`, reached from the RX NAPI polling path. * +1 Adjacent packet-processing reachability. The vulnerable path is in Wi-Fi RX completion and can plausibly be influenced by Wi-Fi peer traffic and STA lifecycle events. This is adjacent network exposure, not routed Internet exposure. * +1 Structured active-object stale use. The stale pointer is not only a cleanup pointer. It is a `wcid` / STA-related active driver object consumed during RX completion processing. Paranoid additional signal: * +1 Stronger unresolved exploitation concern for active network-adjacent UAF. The stale object participates in packet receive processing and STA state handling, and attacker-influenced wireless traffic and association/removal timing may affect the stale-use window. This does not prove controlled reclaim or LPE, but it is enough to avoid auto-downgrade. Non-awarded signals: * Controlled reclaim not demonstrated. * Arbitrary read/write not demonstrated. * Callback or function-pointer control not demonstrated. * Concrete repeated release/refcount mutation not established. * Extra availability point not awarded because the crash is already counted once. * Confidentiality and integrity are not scored as established consequences. The UAF justifies manual review, but C/I impact is not proven by the patch. * Full remote AV:N style Internet reachability is not established. The realistic exposure is Wi-Fi adjacent / link-layer. 3. Reachability analysis The likely attacker is an adjacent Wi-Fi peer or nearby attacker able to influence wireless traffic and STA lifecycle behavior. Host administrator privilege on the victim is not required for that attacker model. This is not a namespace-scoped local privilege case. Network namespaces are not relevant to the supplied trigger. The vulnerable path depends on affected mt7925 hardware and the mt76 driver. That is a deployment prerequisite, but the hardware is not treated as rare physical-only hardware for scoring. The issue is a race between STA removal and RX completion. I did not subtract a generic race penalty because the supplied evidence does not prove the race is one-shot, externally uncontrollable, or impractical to retry. Reliable exploitation beyond crash may still be difficult and is left for manual review. 4. Primitive and severity interpretation The exact primitive is a stale post-lifetime `wcid` pointer use in `mt76_rx_poll_complete` after STA removal. This is a real UAF / lifetime violation. The stale object is an active structured driver object, not fixed stale DMA storage and not merely a destructor-only cleanup pointer. The stale use occurs in RX completion processing, which is more security-relevant than a simple teardown-only fault. No concrete repeated release/refcount operation is shown. No first release followed by a second lifetime mutation on the exact same reference is established. Primitive class is CLASS_B. The demonstrated consequence is kernel crash / DoS. The speculative consequence is possible exploitation of the stale active object if reuse or replacement can be influenced, but controlled reclaim or privilege escalation is not demonstrated. ImportantCandidate=YES because this is a real active-object UAF in a network-adjacent receive path with unresolved exploitation leverage. AutoDowngradeAllowed=NO because automatically closing it as ordinary crash-only Moderate could miss meaningful UAF exploitation risk. Likely operational severity is actionable Moderate at minimum, with Strong Important review warranted if further analysis shows controlled reclaim, useful object replacement, or security-sensitive field consumption. 5. One-sentence report phrase A race in the mt76 mt7925 Wi-Fi RX path can leave rx_status pointing to a removed STA wcid, causing a use-after-free in mt76_rx_poll_complete and at least a network-adjacent kernel crash risk. 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: real UAF in an active Wi-Fi receive path, adjacent attacker influence is plausible, and exploitation leverage beyond DoS is unresolved. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete [ Upstream Commit: aaf414bf81ab4b680580871784b0b929818188eb Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aaf414bf81ab4b680580871784b0b929818188eb 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=aaf414bf81ab4b680580871784b0b929818188eb ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90380 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90380 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:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.5 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: 5 Paranoid ActionableScore: 6 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).