From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64223][MODERATE REGULAR] wifi: mac80211: consume only present negotiated TTLM maps Date: Fri, 24 Jul 2026 12:47:23 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64223 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: 4 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: f7d395dc5008168ac5b9c1ac2791e59a6078cca1 List-Id: CVE: CVE-2026-64223 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: mac80211: consume only present negotiated TTLM maps Commit: f7d395dc5008168ac5b9c1ac2791e59a6078cca1 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f7d395dc5008168ac5b9c1ac2791e59a6078cca1 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64223 Analysis date: Fri, 24 Jul 2026 12:47:23 -0400 ActionableScore: 4 ActionableScore lower bound: 3 Actionable bucket: Borderline manual review recommended / Actionable Moderate candidate if product WiFi MLO exposure is relevant Manual review required: YES Summary: A sparse negotiated TTLM element in mac80211 can cause ieee80211_parse_neg_ttlm() to read past the validated element, allowing an adjacent WiFi attacker to trigger a limited OOB read and possible DoS, while the patch context does not show a direct policy bypass or privilege escalation primitive. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64223 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64223 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-2026-64223 MODERATE CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H';CWE-125;*CWE-20;CWE-1284;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.9';DESCR 'A sparse negotiated TTLM element in mac80211 can make ieee80211_parse_neg_ttlm advance its parser as if map bytes existed for TIDs whose presence bit is clear. This can make a later present TID read past the validated element and copy out of bounds bytes into the negotiated uplink or downlink map state. The bytes are checked against valid_links before being applied, so the patch context does not show a direct policy bypass or privilege escalation primitive. For the CVSS the PR:N because a malicious adjacent WiFi peer or AP can supply malformed management data without needing a local account on the target. The issue is adjacent network reachable rather than Internet reachable and practical impact is mainly denial of service through a kernel warning or crash in hardened or KASAN like configurations. Impact is at least adjacent network denial of service and in worst case may allow limited confidentiality impact from an out of bounds read, so it should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline manual review recommended / Actionable Moderate candidate if product WiFi MLO exposure is relevant (with actual score 4) YES REMOTE KASAN OOB SIMPLEFIX INCREASED_TO_MODERATE_FROM_LOW_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 ActionableScoreLower=3 ## 1. ActionableScore * Conservative score: 3 * Paranoid score: 4 * Final recommended bucket: **Borderline manual review recommended / Actionable Moderate candidate if product WiFi MLO exposure is relevant** ## 2. Signal breakdown * Remote reachable / network-triggerable: +2 Malformed negotiated TTLM data can be supplied by an adjacent WiFi peer or AP. This is not Internet remote, but it is network-triggerable over the wireless medium. * Availability impact realistic: +1 conservative The bug is an OOB read reported by KASAN as slab-out-of-bounds with an exact-sized allocation. Production crash reliability depends on allocator state, so this is not a guaranteed panic, but DoS is plausible. * Broad/common subsystem exposure: +1 mac80211 is a common Linux WiFi stack path, although the affected TTLM/MLO functionality is more specific than ordinary WiFi association handling. * Rare or configuration-dependent feature: -1 Practical triggering likely requires WiFi support for the relevant negotiated TTLM / multi-link operation path and an adjacent attacker in radio range. * Limited read-only OOB primitive: +0 The primitive is an out-of-bounds read, not an OOB write, UAF, double free, type confusion, or arbitrary write. The read bytes are gated by valid_links before being applied to driver state. * Confidentiality impact plausible: +1 paranoid only A limited OOB read exists, but the patch context does not show a clear user-visible disclosure channel. Count this only in the paranoid score. * Reliable kernel crash / strong DoS: +1 paranoid only KASAN demonstrates slab OOB read, but production RX behavior depends on surrounding allocator state. This is plausible enough for paranoid triage, not strong enough for conservative scoring. ## 3. Reachability analysis An adjacent malicious WiFi peer or AP can potentially trigger the parser bug by sending a sparse negotiated TTLM element where some TID presence bits are clear and later TIDs are present. No local account is required on the victim, so this behaves as PR:N for practical CVSS-style reasoning, but the attacker must be in WiFi range and the affected TTLM/MLO path must be in use. Namespaces and containers do not materially affect reachability because the input comes through mac80211 management/protocol parsing rather than a local userspace API. ## 4. Severity interpretation This is not an Important-class candidate based on the provided patch. It is a limited adjacent-network OOB read with plausible DoS but no demonstrated privilege escalation, write primitive, UAF reclaim, type confusion, policy bypass, or information disclosure channel. It is stronger than an ordinary low-risk cleanup because it is network-triggerable in kernel WiFi parsing and KASAN confirms slab OOB behavior, so manual review is reasonable for exposed WiFi products. ## 5. One-sentence report phrase A sparse negotiated TTLM element in mac80211 can cause ieee80211_parse_neg_ttlm() to read past the validated element, allowing an adjacent WiFi attacker to trigger a limited OOB read and possible DoS, while the patch context does not show a direct policy bypass or privilege escalation primitive. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: adjacent-network parser OOB read in mac80211 with KASAN-confirmed slab-out-of-bounds behavior, but no proven write primitive or LPE path. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mac80211: consume only present negotiated TTLM maps Commit: f7d395dc5008168ac5b9c1ac2791e59a6078cca1 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f7d395dc5008168ac5b9c1ac2791e59a6078cca1 Commit description: ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements against the number of link-map entries indicated by link_map_presence. ieee80211_parse_neg_ttlm() must consume the same layout. The parser advanced its cursor for every TID, including TIDs whose presence bit is clear and therefore have no map bytes in the element. A sparse map can then make a later present TID read past the validated element. The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by valid_links before being applied to driver state, so a peer cannot turn the read into a policy change. Under KUnit + KASAN with an exact-sized element allocation the OOB read is reported as a slab-out-of-bounds; whether the same trigger fires under the production RX path depends on surrounding allocator state. Advance the cursor only when the current TID has a map present. Fixes: 8f500fb ("wifi: mac80211: process and save negotiated TID to Link mapping request") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260515151719.1317659-2-michael.bommarito@gmail.com 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=f7d395dc5008168ac5b9c1ac2791e59a6078cca1 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64223 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64223 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:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/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: 3 Paranoid ActionableScore: 4 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).