From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97474][MODERATE REGULAR] wifi: iwlwifi: mld: purge async notifications upon nic error [ Upstream Date: Thu, 24 Sep 2026 20:17:46 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97474 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 3 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 1b3b7b521041d55459f8457db8921e9778482063 List-Id: CVE: CVE-2026-97474 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: iwlwifi: mld: purge async notifications upon nic error [ Upstream Commit: 1b3b7b521041d55459f8457db8921e9778482063 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1b3b7b521041d55459f8457db8921e9778482063 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97474 Analysis date: Thu, 24 Sep 2026 20:17:46 -0400 ActionableScore: 3 ActionableScore lower bound: unknown Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97474 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97474 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: MODERATE REGULAR Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-97474 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97474 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';*CWE-416;CWE-362;*CWE-672;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.9';DESCR 'A use after free can occur in the Intel iwlwifi MLD recovery path when an asynchronous notification from failed firmware is processed after mac80211 has freed a BSS link. The notification handler can dereference a stale fw_id_to_bss_conf entry and cause a kernel panic. The normal trigger requires a complex sequence involving a NIC error, failed recovery of a NAN connection, BSS link teardown, and delayed work execution. For the CVSS the PR:L rating reflects environments where a local user, container service, or delegated network administration context can influence wireless configuration or recovery behavior. The base scenario is local and the adjacent wireless vector is only used for the paranoid assessment because the patch does not prove that a nearby attacker can reliably induce the required firmware error. Impact is at least denial of service through a kernel crash. Limited confidentiality and integrity impact is retained only in the paranoid score because the bug is a kernel use after free, but no controlled memory reuse or write primitive is demonstrated. YES REQUIRES MANUAL CHECK.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3) YES REMOTE DANGER UAF NETWORK LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 3 * Conservative score: 3 * Raw paranoid score: 3 * Paranoid score: 3 * Final recommended bucket: **Borderline / manual review recommended**:: No floor or cap was applied. The supplied evidence establishes a real stale-object dereference and kernel panic, but does not establish attacker-controlled reuse, post-free replacement, a second lifetime mutation, information disclosure, integrity impact, or a practical wireless trigger for the firmware error. 2. Signal breakdown * +2 Real UAF / active lifetime violation. mac80211 frees the BSS link while fw_id_to_bss_conf[id] still points to it, and the asynchronous firmware-notification handler subsequently dereferences that dangling pointer. * +1 Reliable kernel crash / strong DoS. The commit explicitly states that the first access to a freed link field causes a kernel panic. * +0 Firmware-mediated external influence. A firmware error is required, but the supplied evidence does not establish that a nearby wireless attacker can reliably cause the required firmware error and recovery sequence. * +0 Local unprivileged trigger. The complete ability of an ordinary user to establish BSS plus NAN state and drive the required recovery failure is not established. * +0 Controlled reclaim or object replacement. No attacker-controlled allocation reuse, replacement object, or post-free contents are shown. * +0 Structured stale-object exploitation leverage. The stale BSS link is an active structured object, but the demonstrated stale use is a field dereference that immediately panics. No meaningful continued consumption of reused fields, callbacks, offsets, ownership state, or function pointers is established. * +0 Concrete repeated release/refcount operation. No second put, release, free, or refcount mutation on the same dangling BSS link is shown. * +0 Weak LPE concern. A UAF exists, but the patch does not establish a mechanism beyond the crash that could affect credentials, sensitive pointers, authorization state, or another security-relevant object. * +0 Confidentiality and integrity. No disclosure path, attacker-directed write, or unauthorized modification is demonstrated. * +0 Additional Availability. The panic is counted once. There is no distinct persistent availability consequence beyond the same crash. * No negative privilege penalty was applied. Host-admin-equivalent privilege is not positively established. * No hard-race penalty was applied. The sequence involves asynchronous work and recovery failure, but the commit states that async_handlers_wk can be scheduled before reconfiguration work. It does not establish a narrow, externally uncontrollable, or one-shot timing race. 3. Reachability analysis The immediate vulnerable path is an Intel iwlwifi MLD firmware-recovery path. It requires an existing BSS connection, a NAN connection, a firmware NIC error, successful BSS restoration, failed NAN restoration, erroneous mac80211 reconfiguration failure handling, link teardown, and processing of a queued asynchronous firmware notification. The supplied patch does not establish which actor can reliably create the complete BSS plus NAN configuration and cause the required firmware error. It also does not establish that ordinary users can perform the complete sequence below host-admin privilege, nor that CAP_NET_ADMIN in an attacker-controlled network namespace is sufficient. A nearby wireless attacker is not established as a direct trigger. Wireless traffic reaches device firmware only through material firmware and hardware mediation, and no evidence shows that crafted traffic reliably induces this particular NIC error and recovery failure. Therefore, remote or adjacent reachability is not scored as established. No prior host setup, sysctl, boot option, special hardware prerequisite, or namespace-scoped privilege model is sufficiently documented in the supplied material. The affected hardware is Intel WiFi hardware, but no rare-hardware penalty is applied because Intel WiFi devices are broadly deployed and the problem is not merely a device-local initialization quirk. 4. Primitive and severity interpretation The exact primitive is a real use-after-free. A BSS link is freed by mac80211 while the iwlwifi driver retains a stale fw_id_to_bss_conf entry. Later, asynchronous notification processing dereferences that stale pointer. The stale object is an active structured BSS-link-related object rather than fixed DMA storage. However, the demonstrated post-free use is constrained: the notification handler accesses a link field and immediately panics. The evidence does not show controlled replacement of the freed storage, attacker-shaped post-free contents, callback dispatch, arbitrary read or write, or continued processing after reuse. This is not a repeated-release or refcount-mutation case. There is no patch-supported sequence where a first release may destroy the object and a second put, release, free, or refcount decrement mutates the same dangling object. Therefore, the repeated lifetime-mutation signal and the related floor of 5 do not apply. PrimitiveClass is CLASS_B because a genuine kernel lifetime violation and dangling-object dereference are directly established. It is not CLASS_A because there is no controlled reclaim, directed corruption, authorization bypass, callback influence, arbitrary read or write, or demonstrated privilege escalation. The demonstrated consequence is kernel panic and denial of service. Confidentiality, integrity, privilege escalation, and remote wireless triggering remain speculative and are not included in either score. ImportantCandidate is NO because this is presently a constrained crash-capable UAF without demonstrated meaningful exploitation leverage beyond the stale dereference. AutoDowngradeAllowed is YES because the supplied evidence supports a constrained UAF review outcome rather than an unresolved active corruption primitive requiring Important preservation. 5. One-sentence report phrase A stale iwlwifi firmware notification can dereference a BSS link freed by mac80211 during failed NIC recovery and trigger a kernel panic, but the supplied evidence establishes a constrained local or firmware-mediated DoS rather than controlled post-free exploitation. 6. Manual review recommendation MANUAL CHECK RECOMMENDED The bug is a real kernel UAF and should be checked against actual iwlwifi MLD deployments, NAN usage, firmware-error behavior, and reachable wireless recovery paths, but the current patch context supports crash-only impact rather than Important-grade exploitation leverage. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: iwlwifi: mld: purge async notifications upon nic error [ Upstream Commit: 1b3b7b521041d55459f8457db8921e9778482063 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1b3b7b521041d55459f8457db8921e9778482063 Changed files: drivers/net/wireless/intel/iwlwifi/mld/mld.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=1b3b7b521041d55459f8457db8921e9778482063 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97474 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97474 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:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS score: 5.9 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: 3 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: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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).