From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98157][LOW] EDAC/device_sysfs: Use kstrtouint() for poll_msec to prevent truncation [ Upstream Date: Fri, 25 Sep 2026 13:01:52 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98157 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: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: ea01c061d839b520f385f112908de1c6e3391327 List-Id: CVE: CVE-2026-98157 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: EDAC/device_sysfs: Use kstrtouint() for poll_msec to prevent truncation [ Upstream Commit: ea01c061d839b520f385f112908de1c6e3391327 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ea01c061d839b520f385f112908de1c6e3391327 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98157 Analysis date: Fri, 25 Sep 2026 13:01:52 -0400 ActionableScore: 0 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98157 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98157 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-2026-98157 LOW https://www.kernelcve.org/list/?q=CVE-2026-98157 CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';**CWE-400;*CWE-20;CWE-197;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'The EDAC poll_msec sysfs handler can accept zero and can truncate values above UINT_MAX to zero on 64 bit systems. A local actor able to write this attribute can cause EDAC polling work to run without delay and consume CPU resources continuously. For the CVSS the PR:H is used because writing EDAC sysfs configuration is normally restricted to an administrative user. The issue is not network reachable. Impact is denial of service through CPU resource exhaustion. No memory corruption, information disclosure, integrity impact, or privilege escalation primitive is indicated.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) YES WARNONLY SIMPLEFIX HARDWARE LINUS NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 PrimitiveClass=NONE RealUAF=NO HostAdminRequired=YES NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: -1 * Conservative score: 0 * Raw paranoid score: -1 * Paranoid score: 0 * The raw score is normalized to 0 because ActionableScore is non-negative. * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Reliable CPU resource exhaustion. A zero poll_msec value causes EDAC delayed polling work to run without delay and can consume one CPU continuously. * -2 Host-admin-equivalent configuration access. The poll_msec sysfs attribute is an administrative EDAC configuration interface and is normally root writable through sysfs. * No memory-corruption signal awarded. The patch establishes integer truncation and missing input validation, not UAF, OOB access, stale-pointer use, refcount misuse, or overwrite. * No confidentiality or integrity signal awarded. No disclosure, unauthorized modification, ownership violation, or authorization bypass is established. * No remote-reachability signal awarded. The trigger is a local sysfs write. * No additional availability point awarded. The established effect is CPU consumption by the same zero-delay work loop, not a distinct kernel crash, filesystem shutdown, or cross-host exhaustion. * No persistent resource-leak signal awarded. The issue consumes CPU through repeated work scheduling but does not establish a permanently leaked kernel reference or allocation. * No niche-subsystem penalty awarded. EDAC is configuration-dependent, but no evidence shows that its presence is a materially rare or attacker-unreachable prerequisite. 3. Reachability analysis The trigger is a write to the EDAC poll_msec sysfs control attribute. A value of zero is accepted directly by the pre-fix simple_strtoul parsing path. On 64-bit systems, a value greater than UINT_MAX can also be truncated to zero when assigned to the unsigned int poll_msec field. The relevant interface is a host sysfs administrative configuration attribute. The supplied patch does not show a namespace-aware capability check, and EDAC device management concerns host hardware state. The complete trigger is therefore not namespace-scoped. Host-admin-equivalent access is required in normal sysfs permission models. No network input, guest input, device firmware input, special race, special hardware attack, or prior attacker-controlled host setup is required beyond access to the affected EDAC sysfs attribute. EDAC support and an active EDAC device controller must exist, but this is not an exploitation primitive. 4. Primitive and severity interpretation The exact defect is an input-validation and integer-truncation issue. simple_strtoul accepts an unsigned long while poll_msec is an unsigned int. Values above UINT_MAX can truncate during assignment, and zero is accepted despite the intended non-zero delay requirement. The resulting primitive is a zero-delay delayed-work loop that may continuously consume CPU. This is resource exhaustion and availability degradation only. It is not an active structured-object lifetime issue, fixed stale storage issue, cleanup UAF, double release, refcount mutation, OOB access, or security-boundary bypass. PrimitiveClass is NONE because no meaningful corruption, ownership, lifetime, authorization, or similar security primitive is established. The demonstrated consequence is local CPU consumption. A host-wide outage is possible only as a deployment-dependent operational consequence and is not independently established by the patch. ImportantCandidate is NO because this is a privileged local configuration DoS without memory corruption, an isolation failure, or meaningful unresolved exploitation leverage. AutoDowngradeAllowed is YES because the issue can be handled as a low-priority configuration and resource-exhaustion fix. 5. One-sentence report phrase An administrative write of zero or an oversized truncated value to the EDAC poll_msec sysfs attribute can cause polling work to run without delay and consume CPU resources continuously. 6. Manual review recommendation NO MANUAL CHECK NEEDED The patch establishes a bounded privileged local CPU-consumption condition with no kernel memory-corruption, confidentiality, integrity, authorization-bypass, or privilege-escalation primitive. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: EDAC/device_sysfs: Use kstrtouint() for poll_msec to prevent truncation [ Upstream Commit: ea01c061d839b520f385f112908de1c6e3391327 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ea01c061d839b520f385f112908de1c6e3391327 Changed files: drivers/edac/edac_device_sysfs.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=ea01c061d839b520f385f112908de1c6e3391327 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98157 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98157 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.4 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: unknown Paranoid ActionableScore: 0 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).