From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-46125][IMPORTANT] wifi: mac80211: remove station if connection prep fails Date: Thu, 28 May 2026 13:55:16 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-46125 X-AL-KERNEL-Priority: IMPORTANT X-AL-KERNEL-Severity: IMPORTANT X-AL-KERNEL-Base-Severity: IMPORTANT X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 7 X-AL-KERNEL-ActionableScore-Lower: 6 X-AL-KERNEL-Commit: fe75fa1ac9a92990f7fc3d34b17808fd933071b2 List-Id: CVE: CVE-2026-46125 Priority: IMPORTANT AL-KERNEL base severity: IMPORTANT KPANIC flag: YES Patch: wifi: mac80211: remove station if connection prep fails Commit: fe75fa1ac9a92990f7fc3d34b17808fd933071b2 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fe75fa1ac9a92990f7fc3d34b17808fd933071b2 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125 Analysis date: Thu, 28 May 2026 13:55:16 -0400 ActionableScore: 7 ActionableScore lower bound: 6 Actionable bucket: Strong Important candidate / Actionable Moderate at minimum Manual review required: YES Summary: A mac80211 MLO connection preparation failure can leave a stale station associated with a removed vif link, causing debugfs use-after-free or double-free and a potential kernel crash when debugfs is enabled. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46125 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125 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: IMPORTANT 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-2026-46125 IMPORTANT CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H';*CWE-416;CWE-415;CWE-459;Other CVSS 'AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H';BEST CVSS score: '7.1';DESCR 'mac80211 MLO connection preparation failure can leave an existing station attached to a link while the vif is reset from MLD to non MLD. When debugfs is enabled, the MLD transition recreates debugfs state and the stale station link relationship can trigger use-after-free or double-free. For the CVSS the PR:N is used in the paranoid adjacent attacker model because a nearby malicious AP may influence MLO association failure once the client attempts to connect, without needing a local account on the victim. UI:R and AC:H are kept because the victim must attempt WiFi association and the failure path depends on specific MLO state and debugfs exposure. Impact is at least denial of service via kernel crash and in the paranoid case may include confidentiality and integrity impact due to memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7) MAYBE REMOTE LOCK DANGER UAF DEBUGFS KPANIC KPANIC INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=7 ActionableScoreLower=6 ## 1. ActionableScore * Conservative score: **6** * Paranoid score: **7** * Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**:: ## 2. Signal breakdown * Remote or adjacent network influence: **+2**. A nearby AP can plausibly influence MLO association behavior and connection preparation failure, although user association is needed. * Strong memory corruption primitive: **+2**. The commit explicitly says the bug fixes a use-after-free/double-free in debugfs. * Real lifetime corruption: **+1**. A stale station remains tied to a vif link that is removed or recreated during MLD to non-MLD reset. * Weak LPE concern: **+1**. UAF/double-free is a serious class, but no controlled reclaim, overwrite, or privilege escalation primitive is demonstrated. * Reliable kernel crash / strong DoS: **+1**. The realistic impact is kernel crash through debugfs object lifetime corruption. * Availability impact realistic: **+1**. A crash or lockup is plausible once the bad state is reached. * Special conditions: **-1**. Requires MLO connection preparation failure and debugfs enabled, so exploitation is not generic WiFi packet parsing. ## 3. Reachability analysis The bug is reached during mac80211 MLO connection preparation failure. A local user is not necessarily required if a victim device attempts to connect to a nearby malicious or misbehaving MLO AP, but user interaction is likely because the client must initiate or accept association. Containers and namespaces are not central. The issue is not Internet-routable, but it is adjacent wireless reachable in the paranoid model. Practical exploitation depends on MLO support, the failure path, and debugfs being enabled. ## 4. Severity interpretation This is stronger than ordinary Moderate because the patch explicitly mentions UAF/double-free. The realistic demonstrated impact is DoS through kernel memory lifetime corruption in debugfs. Privilege escalation is not proven, and the conditions are constrained, but UAF/double-free in a common wireless subsystem should not be auto-closed without review. ## 5. One-sentence report phrase A mac80211 MLO connection preparation failure can leave a stale station associated with a removed vif link, causing debugfs use-after-free or double-free and a potential kernel crash when debugfs is enabled. ## 6. Manual review recommendation **MANUAL CHECK REQUIRED** Manual review is required because this is explicit UAF/double-free in mac80211, even though it is gated by MLO failure handling and debugfs exposure. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mac80211: remove station if connection prep fails Commit: fe75fa1ac9a92990f7fc3d34b17808fd933071b2 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fe75fa1ac9a92990f7fc3d34b17808fd933071b2 Commit description: If connection preparation fails for MLO connections, then the interface is completely reset to non-MLD. In this case, we must not keep the station since it's related to the link of the vif being removed. Delete an existing station. Any "new_sta" is already being removed, so that doesn't need changes. This fixes a use-after-free/double-free in debugfs if that's enabled, because a vif going from MLD (and to MLD, but that's not relevant here) recreates its entire debugfs. Cc: stable@vger.kernel.org Fixes: 81151ce ("wifi: mac80211: support MLO authentication/association with one link") Reviewed-by: Miriam Rachel Korenblit Link: https://patch.msgid.link/20260505151533.c4e52deb06ad.Iafe56cec7de8512626169496b134bce3a6c17010@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman Changed files: net/mac80211/mlme.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=fe75fa1ac9a92990f7fc3d34b17808fd933071b2 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46125 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125 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:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.1 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: 6 Paranoid ActionableScore: 7 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: IMPORTANT KPANIC detected for this report: YES Published priority for this report (same as in Subject): IMPORTANT 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).