From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98746][LOW] serial: ma35d1: Fix clock reference leak in ma35d1serial_probe() Date: Sat, 24 Oct 2026 09:03:09 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98746 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: unknown X-AL-KERNEL-Commit: 547c742f3b4acd4634eec47e9bff8731b55059a0 List-Id: CVE: CVE-2026-98746 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: serial: ma35d1: Fix clock reference leak in ma35d1serial_probe() Commit: 547c742f3b4acd4634eec47e9bff8731b55059a0 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=547c742f3b4acd4634eec47e9bff8731b55059a0 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98746 Analysis date: Sat, 24 Oct 2026 09:03:09 -0400 ActionableScore: 1 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: The MA35D1 serial driver omitted `clk_put()` on probe failures and removal, causing a constrained clock-reference leak without demonstrated memory corruption or material denial of service. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98746 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98746 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-2026-98746 LOW https://www.kernelcve.org/list/?q=CVE-2026-98746 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (final reconciliation agrees; DECISION: both LOW) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';*CWE-772;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '3.3';DESCR 'The ma35d1 serial driver leaks the clock reference returned by of_clk_get on probe error paths and whenever a bound port is removed. Repeated device lifecycle operations can retain clock references, but the available evidence does not establish rapid or host wide resource exhaustion. There is no UAF, OOB access, information leak, arbitrary write, or supported privilege escalation primitive. For the CVSS the PR:L value in the paranoid score reflects a deployment where limited device management is delegated, while ordinary systems generally require stronger administrative control. The issue is local and is not reachable through serial input or network traffic. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 3.3 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. No severity changing production threshold or specialist override was recorded. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. The independent weaker Aegis shadow evaluated CVSS 0.0 and ActionableScore 0 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was LOW. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) MAYBE PRINTF-TTY SIMPLEFIX LEAK ERRORPATH LINUS - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 1. * Conservative score: 1; no floor or cap applies. * Raw paranoid score: 1. * Paranoid score: 1; no technically supported additional impact. * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Concrete persistent kernel resource/reference leak: `of_clk_get()` acquires a clock reference, while probe failures and device removal previously omitted the matching `clk_put()`. * No reliable DoS point: repeated lifecycle operations could accumulate references, but host-wide exhaustion or another material availability effect is not shown. * No hardware or privilege penalty: the MA35D1 platform dependency and lifecycle permissions are apparent, but the supplied evidence does not establish sufficiently rare hardware or a host-admin-only complete trigger. * No UAF, OOB access, memory overwrite, authorization bypass, disclosure, or integrity primitive is shown. * NEW52 B5-R and NEW53 B3-PENDING do not apply: there is no write beyond an allocation or write to shared backing. 3. Reachability analysis The defect occurs during platform-driver probe failure and device removal. The patch does not establish that an ordinary user, namespace capability holder, or delegated service can initiate the complete bind/unbind or probe-failure sequence. Host-admin and UID-0 requirements therefore remain unknown rather than proven. There is no network or serial-input trigger, no race, and no shown namespace-scoped path. 4. Primitive and severity reading The exact defect is a leaked clock reference, not stale-object use or repeated release. It may retain clock-provider resources across failed probes or removals, but rapid accumulation and host-wide exhaustion are unproven. This is constrained resource-lifetime behavior classified as CLASS_C, with no Important-grade leverage or unresolved security boundary. Automatic downgrade is safe. 5. One-sentence report phrase The MA35D1 serial driver omitted `clk_put()` on probe failures and removal, causing a constrained clock-reference leak without demonstrated memory corruption or material denial of service. 6. Manual review advice NO MANUAL CHECK NEEDED The patch fully identifies a low-impact reference leak with no supported stronger primitive. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: serial: ma35d1: Fix clock reference leak in ma35d1serial_probe() Commit: 547c742f3b4acd4634eec47e9bff8731b55059a0 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=547c742f3b4acd4634eec47e9bff8731b55059a0 Commit description: of_clk_get() returns a clock with a reference that has to be released with clk_put(). ma35d1serial_probe() never does that, so the reference is leaked on the probe error paths and also when the port is removed. Release it on the error paths and in ma35d1serial_remove(). Fixes: 930cbf9 ("tty: serial: Add Nuvoton ma35d1 serial driver support") Cc: stable@kernel.org Signed-off-by: Wentao Liang Link: https://patch.msgid.link/20260917155650.2161274-1-vulab@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman Changed files: drivers/tty/serial/ma35d1_serial.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=547c742f3b4acd4634eec47e9bff8731b55059a0 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98746 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98746 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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS score: 3.3 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: unknown 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).