From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64144][LOW] Bluetooth: btmtk: fix urb->setup_packet leak in error paths [ Upstream Date: Sun, 19 Jul 2026 12:38:42 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64144 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 1 X-AL-KERNEL-ActionableScore-Lower: 0 X-AL-KERNEL-Commit: 2a1905730e0c771b999906a7b509722f795563c6 List-Id: CVE: CVE-2026-64144 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: Bluetooth: btmtk: fix urb->setup_packet leak in error paths [ Upstream Commit: 2a1905730e0c771b999906a7b509722f795563c6 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2a1905730e0c771b999906a7b509722f795563c6 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64144 Analysis date: Sun, 19 Jul 2026 12:38:42 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: Bluetooth btmtk can leak a control URB setup_packet allocation when usb_submit_urb fails or a submitted URB is killed, causing only limited resource exhaustion risk through device-specific error paths. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64144 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64144 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: LOW 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-2026-64144 LOW CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L';*CWE-401;*CWE-772;CWE-404;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '2.4';DESCR 'Bluetooth btmtk can leak the setup_packet allocation for a control URB when usb_submit_urb fails or when the submitted URB is killed with ENOENT. A realistic attacker model is physical access with a malicious or unstable MediaTek USB Bluetooth device, or local administrative control over device reset and driver error paths. For the CVSS the PR:N is used for the physical attack model because a USB device does not require a local user account on the victim. The issue is not network reachable. Impact is limited denial of service through gradual kernel memory consumption, with no evidence of memory corruption, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) YES LEAK ERRORPATH UAF HARDWARE NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like** ## 2. Signal breakdown Triggered or considered signals: * Availability impact realistic: +1 in paranoid only. The bug can leak small kernel allocations on repeated URB error paths, but the impact is gradual and not shown to cause immediate system-wide failure. * Physical-only or device-specific condition: -2. The most plausible unprivileged attacker model requires a malicious or unstable MediaTek USB Bluetooth device, or physical/device-level influence. * Rare and difficult-to-reach subsystem/configuration: -1 conservative. The affected path is specific to MediaTek btmtk USB Bluetooth handling and specific URB failure or kill paths. * No generic memory corruption: +0. The patch only adds missing kfree calls and does not show UAF, double-free, OOB access, type confusion, stale callback, or refcount misuse. * No privilege escalation signal: +0. There is no demonstrated reclaim, overwrite, object replacement, or security boundary bypass. * No remote/network reachability: +0. Bluetooth host stack networking is not the trigger here. The trigger is USB URB error handling. ## 3. Reachability analysis A realistic trigger requires either physical access with a MediaTek USB Bluetooth device that can cause repeated control URB submission failures or URB kill paths, or local administrative control over device reset, suspend, unload, or driver error handling. A normal remote network attacker cannot reach this path. Namespaces and containers do not materially lower the privilege requirement because USB device management and driver reset paths are normally host-controlled. The affected driver is hardware-specific and the leak is in error handling, so practical exploitation conditions are narrow. ## 4. Severity interpretation This behaves like a Low-like resource leak rather than an actionable Moderate or Important kernel vulnerability. The theoretical impact is denial of service through accumulated kernel memory consumption, but the leaked object is small and the patch does not show memory corruption, information disclosure, integrity impact, or privilege escalation. Conservative triage can treat it as auto-close eligible unless product-specific evidence shows repeated automatic triggering at scale. ## 5. One-sentence report phrase Bluetooth btmtk can leak a control URB setup_packet allocation when usb_submit_urb fails or a submitted URB is killed, causing only limited resource exhaustion risk through device-specific error paths. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This is a small resource leak in hardware-specific Bluetooth USB error paths, with no concrete memory corruption primitive, no remote reachability, and no plausible privilege escalation path shown by the patch. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: Bluetooth: btmtk: fix urb->setup_packet leak in error paths [ Upstream Commit: 2a1905730e0c771b999906a7b509722f795563c6 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2a1905730e0c771b999906a7b509722f795563c6 Changed files: drivers/bluetooth/btmtk.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=2a1905730e0c771b999906a7b509722f795563c6 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64144 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64144 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:H/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS score: 2.4 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: 0 Paranoid ActionableScore: 1 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: LOW KPANIC detected for this report: NO Published priority for this report (same as in Subject): LOW 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).