From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97479][LOW] driver core: Avoid warning when removing a device while its supplier is unbinding [ Upstream Date: Thu, 24 Sep 2026 19:08:22 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97479 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: 73ea4ec0ec46d12558a61842b474e7dd63538edc List-Id: CVE: CVE-2026-97479 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: driver core: Avoid warning when removing a device while its supplier is unbinding [ Upstream Commit: 73ea4ec0ec46d12558a61842b474e7dd63538edc Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=73ea4ec0ec46d12558a61842b474e7dd63538edc Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97479 Analysis date: Thu, 24 Sep 2026 19:08:22 -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-2026-97479 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97479 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-2026-97479 LOW https://www.kernelcve.org/list/?q=CVE-2026-97479 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:N';CWE-391;BEST CVSS score: '0';DESCR 'A driver core warning can be emitted during a valid nested device supplier and consumer unbind sequence when the supplier is already in the DL_DEV_UNBINDING state. The condition is a diagnostic false positive during driver removal and does not demonstrate memory corruption, an access control bypass, a kernel crash, or a denial of service. For the CVSS the PR:H reflects that driver registration removal and device teardown are normally administrative operations. The issue is not network reachable and has no confidentiality integrity or availability impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) YES WARNONLY HARDWARE LINUS NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 PrimitiveClass=NONE RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 0 * Conservative score: 0 * Raw paranoid score: 0 * Paranoid score: 0 * Final recommended bucket: **Ordinary Moderate**:: The patch is a diagnostic warning suppression for a valid nested device link unbind ordering. There is no established security primitive, crash, corruption, resource leak, authorization bypass, or availability impact. 2. Signal breakdown * +0 No memory corruption primitive. The patch neither allocates nor frees memory and does not alter reference counting, object lifetime, pointer ownership, or memory access bounds. * +0 No real UAF. The supplier device is in the valid DL_DEV_UNBINDING lifecycle state, not freed or accessed after its lifetime ended. * +0 No security boundary or authorization issue. The changed condition only recognizes DL_DEV_UNBINDING as an allowed supplier state while processing consumer removal. * +0 No reliable DoS. WARN_ON is the documented behavior and the patch does not establish a panic, Oops, deadlock, hang, device failure, or persistent availability impact. * +0 No remote reachability. The path is driver-core teardown logic, not packet or externally exposed protocol processing. * +0 No confidentiality or integrity impact. No disclosure, modification of protected data, privilege escalation, or policy bypass is established. Important non-awarded signals: * Controlled reclaim not demonstrated. * Arbitrary write not demonstrated. * Concrete stale-object access not demonstrated. * Concrete repeated release or refcount mutation not demonstrated. * Remote reachability not established. * Privilege escalation is not indicated. * Extra availability impact is not awarded because the observed behavior is only a non-fatal diagnostic warning. 3. Reachability analysis The affected code executes during nested device supplier and consumer driver unbind operations. The supplied example involves removal of a PCI-backed topology containing an interrupt controller, pinctrl device, and I2C consumer. The provided patch does not establish an attacker-controlled interface to trigger this removal ordering. Driver registration, unregistration, module removal, and device teardown are normally administrative or hardware lifecycle operations, but the complete privilege boundary is not shown in the supplied context. Therefore HostAdminRequired is UNKNOWN rather than YES. No namespace-scoped capability path is shown. A network namespace, user namespace, container, delegated capability, or ordinary local user trigger is not established. NamespaceScopedPrivilege is UNKNOWN. There is no network trigger, no special attacker-controlled payload, no demonstrated race, and no evidence that a remote party can influence the device link unbind sequence. 4. Primitive and severity interpretation The exact issue is an overly strict diagnostic assertion in __device_links_no_driver. Before the change, the code warned whenever the supplier was not DL_DEV_DRIVER_BOUND unless the device link had DL_FLAG_SYNC_STATE_ONLY. The patch recognizes that DL_DEV_UNBINDING is also valid while recursive consumer unbinding is still in progress. This is not an active lifetime violation. The supplier remains a live device object whose link status legitimately changes to DL_DEV_UNBINDING during teardown. The patch does not delay a free, add synchronization, repair ownership, alter reference counts, prevent a stale dereference, or change an authorization decision. PrimitiveClass is NONE. RealUAF is NO. The demonstrated consequence is only a false-positive WARN_ON message. No plausible patch-supported consequence beyond diagnostic log noise is established. ImportantCandidate is NO because there is no unresolved corruption, ownership, lifetime, semantic reinterpretation, or security-boundary primitive. AutoDowngradeAllowed is YES because automatic closure would not discard a meaningful security issue. Likely operational severity is non-security correctness and diagnostic cleanup. 5. One-sentence report phrase This patch suppresses a false positive driver core warning during a valid nested device supplier and consumer unbind sequence and does not establish a security impact. 6. Manual review recommendation NO MANUAL CHECK NEEDED The patch only corrects a WARN_ON condition for a valid DL_DEV_UNBINDING state and provides no evidence of memory corruption, use-after-free, denial of service, privilege escalation, or externally reachable attack surface. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: driver core: Avoid warning when removing a device while its supplier is unbinding [ Upstream Commit: 73ea4ec0ec46d12558a61842b474e7dd63538edc Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=73ea4ec0ec46d12558a61842b474e7dd63538edc Changed files: drivers/base/core.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=73ea4ec0ec46d12558a61842b474e7dd63538edc ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97479 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97479 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: Not available The Best / paranoid CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:N The Best / paranoid CVSS score: 0 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).