From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64463][MODERATE 7.0] usb: typec: tcpci_rt1711h: unregister TCPCI port with devres Date: Sat, 25 Jul 2026 15:33:46 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64463 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: ce2e36e8759dfbfe546723810c306f42f484866d List-Id: CVE: CVE-2026-64463 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: usb: typec: tcpci_rt1711h: unregister TCPCI port with devres Commit: ce2e36e8759dfbfe546723810c306f42f484866d Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ce2e36e8759dfbfe546723810c306f42f484866d Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64463 Analysis date: Sat, 25 Jul 2026 15:33:46 -0400 ActionableScore: 5 ActionableScore lower bound: 2 Actionable bucket: Actionable Moderate at minimum Manual review required: NO Summary: A missing unregister on the rt1711h TCPCI probe failure path can leave a stale registered Type C TCPM object after partial initialization, creating a local DoS and possible UAF-style lifetime risk in device-management scenarios. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64463 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64463 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-64463 MODERATE CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-459;*CWE-772;*CWE-416;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '7';DESCR 'rt1711h_probe registers a TCPCI port before requesting the IRQ and enabling alert handling. If a later probe step fails, the driver can return without unregistering the port, leaving a registered Type C TCPM object tied to a failed device probe. This is primarily a local driver lifetime and cleanup flaw, but the stale registered port can plausibly keep callbacks or sysfs visible after related devres managed state is unwound. For the CVSS the PR:L is used in the paranoid score because a reduced capability local actor, a service controlling driver bind operations, or a container with delegated device management could trigger reprobe or failure paths without full host administration. The issue is not network reachable. Impact is at least local denial of service through leaked or stale kernel objects, and worst case may involve UAF style access if the orphaned TCPCI port is used after probe cleanup.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4) YES REMOTE USB INIT SIMPLEFIX NETWORK LINUS TEST DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: ## 2. Signal breakdown Conservative signals: * Real lifetime corruption: +1. The driver registers a TCPCI port and can later fail probe without unregistering it, leaving an object lifetime mismatch. * Privileged kernel/device-management lifetime path: +1. The bug is in a Type-C controller driver probe/unwind path and affects registration state of a kernel-managed TCPCI/TCPM object. * Availability impact realistic: +1. A stale registered port can plausibly leave the Type-C device state inconsistent or broken after failed probe. * Requires admin/root/device-management control in typical deployments: -2. Reliable triggering usually requires driver bind/unbind, reprobe, fault injection, or device-management control. * Rare and hardware-specific condition: -1. The affected path requires this specific rt1711h TCPCI controller and a probe failure after tcpci_register_port succeeds. Paranoid additional signals: * Weak/indirect corruption candidate: +1. The stale registered TCPCI port may remain reachable after devres-managed state is unwound, creating a possible stale pointer or UAF-style candidate. * Weak LPE concern: +1. This is not a demonstrated exploit primitive, but stale registered kernel objects with callbacks or sysfs/control-plane exposure deserve manual review. * Local reduced-privilege trigger interpretation: +1. In some environments, reprobe or bind/unbind control may be delegated to a service, container root, or reduced-capability local actor rather than full host root. ## 3. Reachability analysis The bug is not network reachable. It is reached through the local driver probe error path after tcpci_register_port succeeds but before IRQ setup or alert enabling completes. In normal deployments, triggering requires the specific rt1711h Type-C controller and a probe failure at the right stage. A regular unprivileged user typically cannot force this path. Root, driver-management services, test/fault-injection setups, or delegated device-management environments may be able to trigger reprobe or failure paths. Namespaces and containers only matter if device bind/unbind, I2C device control, or relevant driver-management operations are delegated. Without such delegation, this remains a privileged local/hardware-specific issue. Call-site confidence: medium. The changed code directly shows the registration and missing unregister error path, but the later reachability of the stale TCPCI/TCPM object depends on surrounding subsystem behavior not fully included in the patch. ## 4. Severity interpretation This behaves conservatively like a low-to-moderate local device-management cleanup bug with possible DoS from stale kernel objects. The patch does not demonstrate attacker-controlled reclaim, arbitrary write, type confusion, or a concrete privilege-escalation primitive. The paranoid interpretation is stronger because TCPCI port registration is a real kernel object lifetime boundary. Leaving the port registered after probe failure could plausibly expose stale callbacks or sysfs/control-plane paths after related resources are unwound. That makes it an Actionable Moderate candidate for manual review, but not a strong Important candidate without more evidence. ## 5. One-sentence report phrase A missing unregister on the rt1711h TCPCI probe failure path can leave a stale registered Type C TCPM object after partial initialization, creating a local DoS and possible UAF-style lifetime risk in device-management scenarios. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Manual review is recommended because the conservative impact is low, but the bug crosses a kernel object registration and devres unwind boundary. The main question is whether the orphaned TCPCI port remains reachable through callbacks, sysfs, workqueues, or TCPM state after probe cleanup. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: usb: typec: tcpci_rt1711h: unregister TCPCI port with devres Commit: ce2e36e8759dfbfe546723810c306f42f484866d Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ce2e36e8759dfbfe546723810c306f42f484866d Commit description: rt1711h_probe() registers the TCPCI port before requesting the interrupt and enabling alert interrupts. If either of those later steps fails, the probe function returns without unregistering the TCPCI port. The explicit unregister currently only happens from the remove callback. Register a devres action immediately after tcpci_register_port() succeeds, so tcpci_unregister_port() runs on later probe failures and on driver detach. Drop the remove callback to avoid unregistering the same port twice. This issue was identified during our ongoing static-analysis research while reviewing kernel code. Fixes: 302c570 ("usb: typec: tcpci_rt1711h: avoid screaming irq causing boot hangs") Cc: stable Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Signed-off-by: Myeonghun Pak Link: https://patch.msgid.link/20260706145312.37260-1-mhun512@gmail.com Signed-off-by: Greg Kroah-Hartman Changed files: drivers/usb/typec/tcpm/tcpci_rt1711h.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=ce2e36e8759dfbfe546723810c306f42f484866d ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64463 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64463 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:H/PR:H/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7 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: 2 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: NO 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).