From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-45925][LOW] thermal/of: Fix reference leak in thermal_of_cm_lookup() [ Upstream Date: Wed, 27 May 2026 21:06:41 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-45925 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: 8af710156c53cdb392d529497ef2b3a10a1f9370 List-Id: CVE: CVE-2026-45925 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: thermal/of: Fix reference leak in thermal_of_cm_lookup() [ Upstream Commit: 8af710156c53cdb392d529497ef2b3a10a1f9370 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8af710156c53cdb392d529497ef2b3a10a1f9370 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45925 Analysis date: Wed, 27 May 2026 21:06:41 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A thermal OF cleanup bug leaks a `device_node` reference from `of_parse_phandle()` during cooling-map lookup, causing a low-risk platform-specific resource leak without memory corruption or privilege escalation. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45925 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45925 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-2026-45925 LOW CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';*CWE-772;*CWE-401;CWE-404;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.1';DESCR 'thermal_of_cm_lookup leaked a device_node reference returned by of_parse_phandle when walking thermal cooling map entries. This can accumulate references on Device Tree based systems during thermal binding or lookup activity, but the bug is a resource leak rather than kernel memory corruption. For the CVSS the PR:H is used because reliable triggering typically requires control over thermal device binding, platform configuration, or privileged device management rather than ordinary unprivileged local access. The issue is not network reachable. Impact is limited to availability through potential resource leakage, with no supported evidence of information disclosure, integrity impact, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) MAYBE INIT SIMPLEFIX LEAK HARDWARE - - 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 * Availability impact realistic: +1 in paranoid scoring only Repeated reference leaks could theoretically accumulate and degrade thermal subsystem behavior or memory usage, but no immediate system-wide failure is shown. * Requires admin/root/platform control in typical deployments: -2 conservative Reliable triggering usually depends on thermal device binding, Device Tree based platform configuration, driver probing, or privileged device-management paths. * Rare AND difficult-to-reach subsystem/configuration: -1 conservative This is specific to Device Tree thermal cooling-map lookup behavior and is not a broad userspace-facing interface. * No local unprivileged trigger: +0 The patch does not indicate that an ordinary local user can repeatedly trigger the lookup. * No memory corruption: +0 This is a missing `device_node` reference release, not UAF, double-free, OOB write, arbitrary write, or type confusion. * No privilege escalation or confidentiality impact: +0 The leaked reference does not expose data, bypass permissions, or alter security policy. ## 3. Reachability analysis The bug is reachable in the thermal OF cooling-map lookup path on Device Tree based systems. In normal deployments, this path is exercised during platform thermal setup, device binding, or thermal driver activity, not through an ordinary unprivileged syscall or network input. Containers and namespaces do not materially lower the privilege requirement unless a product exposes thermal device rebinding or platform device management to untrusted users, which is uncommon. The issue is not network reachable. Realistic exploitation is limited to resource leakage under repeated privileged or platform-triggered lookup activity. ## 4. Severity interpretation This behaves like Low or ordinary Moderate. The realistic impact is a reference leak with possible resource exhaustion only under repeated triggering. There is no kernel memory corruption, no sensitive object access, no policy bypass, and no practical privilege escalation evidence. The paranoid score only accounts for limited availability impact if the leak can be accumulated in a specific downstream environment. ## 5. One-sentence report phrase A thermal OF cleanup bug leaks a `device_node` reference from `of_parse_phandle()` during cooling-map lookup, causing a low-risk platform-specific resource leak without memory corruption or privilege escalation. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This is a platform-specific reference leak with no demonstrated unprivileged trigger, no network exposure, and no memory corruption or security-boundary bypass. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: thermal/of: Fix reference leak in thermal_of_cm_lookup() [ Upstream Commit: 8af710156c53cdb392d529497ef2b3a10a1f9370 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8af710156c53cdb392d529497ef2b3a10a1f9370 Changed files: drivers/thermal/thermal_of.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=8af710156c53cdb392d529497ef2b3a10a1f9370 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45925 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45925 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.1 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).