From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-93790][MODERATE REGULAR] wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif [ Upstream Date: Thu, 24 Sep 2026 18:32:22 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-93790 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: 2 X-AL-KERNEL-ActionableScore-Lower: 1 X-AL-KERNEL-Commit: c48b741277b01b2c3b4ecccedc72fc575b71dc04 List-Id: CVE: CVE-2026-93790 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif [ Upstream Commit: c48b741277b01b2c3b4ecccedc72fc575b71dc04 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c48b741277b01b2c3b4ecccedc72fc575b71dc04 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93790 Analysis date: Thu, 24 Sep 2026 18:32:22 -0400 ActionableScore: 2 ActionableScore lower bound: 1 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-2026-93790 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93790 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-93790 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-93790 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:N/UI:N/S:U/C:H/I:H/A:H';*CWE-787;CWE-125;*CWE-20;*CWE-787;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7.5';DESCR 'An out of bounds kernel memory write can occur in the Intel iwlwifi MVM Block Ack notification handler when a compressed BA notification contains a TID outside the mvmsta tid_data array bounds. The vulnerable path processes firmware supplied notification data and writes lq_color through the resulting array index. An adjacent attacker may need to cause a malformed wireless Block Ack condition that is accepted and reported by the device firmware. For the CVSS the PR:N is used because no local account or privileges on the victim are required. The attack vector is adjacent AV:A because the attacker needs wireless proximity to a vulnerable active WiFi adapter. The base impact is denial of service through kernel memory corruption. The paranoid impact includes C:H I:H A:H because an out of bounds kernel write can potentially provide a stronger corruption primitive, but exploitation reliability depends on firmware behavior and target specific memory layout. YES REQUIRES MANUAL CHECK.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES REMOTE WRITE OOB SIMPLEFIX NETWORK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=1 PrimitiveClass=CLASS_B RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 1 * Conservative score: 1 * Raw paranoid score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate**:: No floor or cap was applied. 2. Signal breakdown Conservative: * +1 Constrained kernel overwrite. The patch adds a bounds check before writing `lq_color` through `mvmsta->tid_data[tid]`. An invalid TID can cause an out of bounds write, but the patch establishes only a constrained field write. It does not establish attacker selected payload contents, target selection, controlled object replacement, arbitrary write, or a callback primitive. Paranoid: * +1 Constrained kernel overwrite. Same established primitive. * +1 Firmware-mediated external influence. The vulnerable notification is received from Intel WiFi firmware and is associated with Block Ack processing. A nearby wireless peer may influence the condition through malformed or unusual wireless protocol traffic, but the supplied evidence does not establish that an attacker can reliably make firmware emit an invalid TID notification. Non-awarded material signals: * No direct remote reachable bonus. The affected value is firmware supplied, and the patch does not prove that arbitrary network traffic directly reaches the invalid TID state. * No reliable kernel crash bonus. The patch prevents an out of bounds write but does not document a kernel panic, Oops, or other demonstrated host wide DoS result. * No strong corruption bonus. There is no demonstrated attacker controlled write payload, meaningful target selection, controlled reclaim, type confusion, callback influence, refcount takeover, or arbitrary kernel read or write. * No confidentiality or integrity bonus. The patch does not establish a disclosure path, protected object overwrite, credential modification, or persistent integrity consequence. * No local unprivileged trigger bonus. The evidence does not prove that an ordinary local user can cause the firmware to deliver the invalid notification. * No host administrator penalty. Host-admin-equivalent privilege is not positively established as necessary for the complete trigger. * No hardware rarity penalty. Intel WiFi devices are common enough that the driver location alone is not a rare-hardware condition. * No race penalty. This is input validation and array bounds handling, not a demonstrated timing race. 3. Reachability analysis The vulnerable function processes a compressed Block Ack notification delivered by the Intel iwlwifi firmware. The relevant immediate input is firmware-originated rather than a userspace ioctl, local control-plane API, or directly parsed host network packet. A nearby wireless peer could potentially influence Block Ack processing by interacting with a vulnerable active WiFi interface. However, the supplied patch does not establish that a malicious access point or station can reliably cause the firmware to construct a notification with a TID outside the valid `tid_data` range. Firmware validation and protocol parsing are material intermediate stages. No local account on the victim is inherently required if the malformed firmware notification is externally inducible. Nevertheless, below-host-admin reachability of the complete trigger is not positively established by the patch. Therefore HostAdminRequired is UNKNOWN rather than NO. No user namespace, network namespace, delegated capability, sysctl, boot option, or prior host-admin setup requirement is shown in the supplied context. NamespaceScopedPrivilege is UNKNOWN because no namespace-based trigger path is involved or established. 4. Primitive and severity interpretation The exact primitive is a constrained out of bounds kernel field write in `mvmsta->tid_data[tid].lq_color` when `tid` is outside the array bounds. The prior code also used the TFD loop index `i` instead of the actual TID, causing writes to an incorrect per-TID slot. The fix both corrects the index and validates the actual TID. This is not a UAF, stale-object use, refcount bug, double release, RCU issue, ownership violation, or authorization bypass. It is an OOB write with limited demonstrated control. The patch does not show the range of attacker influence over `tid`, the type and size of `lq_color`, adjacent objects or fields, or a path from the write to meaningful corruption. The primitive is classified as CLASS_B because a concrete kernel out of bounds write exists and deserves review, but it is constrained. The patch-supported demonstrated consequence is incorrect or out of bounds kernel state modification. A crash is plausible but not demonstrated. Privilege escalation, information disclosure, arbitrary kernel write, and controlled memory reuse remain speculative. ImportantCandidate is NO because the patch does not establish meaningful exploitation leverage beyond the constrained write. AutoDowngradeAllowed is YES because no controlled payload, controlled target, active-object replacement, security-boundary bypass, or unresolved lifetime corruption is established. Manual review remains recommended because the bounds check protects a kernel array write and firmware behavior may require hardware-specific validation. 5. One-sentence report phrase A constrained out of bounds write in the Intel iwlwifi Block Ack notification handler can occur when firmware supplies an invalid TID, but practical attacker control over the malformed firmware notification and the resulting corruption impact are not established. 6. Manual review recommendation MANUAL CHECK RECOMMENDED The patch fixes a concrete kernel out of bounds write, but manual review should determine whether malformed wireless Block Ack traffic can reliably cause the firmware to emit an invalid TID and whether the write can affect security-relevant adjacent state. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif [ Upstream Commit: c48b741277b01b2c3b4ecccedc72fc575b71dc04 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c48b741277b01b2c3b4ecccedc72fc575b71dc04 Changed files: drivers/net/wireless/intel/iwlwifi/mvm/tx.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=c48b741277b01b2c3b4ecccedc72fc575b71dc04 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-93790 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93790 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:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.5 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: 1 Paranoid ActionableScore: 2 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).