From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64176][LOW] wifi: iwlwifi: mvm: fix driver-set TX rates on old devices Date: Sun, 19 Jul 2026 14:17:36 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64176 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: 1 X-AL-KERNEL-ActionableScore-Lower: 0 X-AL-KERNEL-Commit: 6fe92651b44fd3cfc8dcfdaad0e82885c384dada List-Id: CVE: CVE-2026-64176 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: wifi: iwlwifi: mvm: fix driver-set TX rates on old devices Commit: 6fe92651b44fd3cfc8dcfdaad0e82885c384dada Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6fe92651b44fd3cfc8dcfdaad0e82885c384dada Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64176 Analysis date: Sun, 19 Jul 2026 14:17:36 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: Incorrect legacy TX rate encoding in iwlwifi mvm can cause old Intel WiFi devices to receive invalid TX or beacon rate values, potentially triggering firmware assert or wireless availability loss, but no kernel memory corruption or privilege escalation primitive is indicated. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64176 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64176 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-2026-64176 LOW CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';CWE-682;CWE-670;CWE-754;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '3.3';DESCR 'Incorrect legacy TX rate encoding in iwlwifi mvm can make old Intel Wi-Fi devices send wrong TX_CMD or beacon template rates to firmware. On affected devices such as 7265D this can trigger a firmware assert or warning and may cause loss of wireless availability, but the patch does not indicate kernel memory corruption, information disclosure, or privilege escalation. For the CVSS the PR:L reflects a conservative environment where a local user or delegated network service can influence wireless configuration through limited network administration rights. In typical deployments full administrator privileges may be required, so the practical base score is lower. The issue is not directly network reachable from the Internet and is tied to local driver configuration and old device firmware behavior. Impact is denial of service or wireless device disruption only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) YES REMOTE DANGER NETWORK HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like** ## 2. Signal breakdown Conservative signals: * Availability impact realistic: +1. Incorrect TX rate encoding can trigger firmware assert/crash or warning, causing WiFi device disruption. * Requires admin/root/CAP_NET_ADMIN in typical deployments: -2. Triggering relevant beacon or interface configuration normally requires privileged wireless configuration control. * Legacy / non-default hardware path: -1. The issue is specific to older devices such as Intel 7265D and old firmware rate encoding. Paranoid adjustment: * Reliable device-level DoS concern: +1. If the affected old device is configured in the relevant mode, the firmware assert/crash may be reproducible enough to disrupt wireless availability. Not applied: * No generic memory corruption. The patch fixes rate encoding logic, not UAF, OOB write, double free, refcount misuse, or type confusion. * No privilege escalation plausible. There is no shown reclaim, overwrite, callback, stale pointer, or object confusion primitive. * No remote reachable signal. The issue is not triggered by ordinary network packets from the Internet. * No firmware-mediated external influence. The firmware is affected by driver-provided values, but the patch does not show attacker-controlled firmware input or malicious firmware data shaping. Call-site confidence: high. The patch includes the relevant call sites in beacon flag construction and TX command rate construction. ## 3. Reachability analysis The likely trigger requires an affected Intel iwlwifi old device and a configuration path that causes the driver to set legacy TX or beacon rates. In typical deployments this is controlled by root or a process with CAP_NET_ADMIN through wireless interface setup, AP mode, or managed network configuration. A reduced-privilege service with delegated network administration could lower the practical privilege assumption, but this still does not become a remote unauthenticated network attack. The path is hardware and firmware-version dependent and does not apply broadly to all iwlwifi devices. ## 4. Severity interpretation This behaves like a low severity driver correctness and availability issue rather than an Important-class kernel vulnerability. The realistic impact is firmware assert/crash, warning, or loss of wireless functionality on affected old devices. Theoretical kernel compromise is not supported by the patch because there is no memory lifetime bug, attacker-controlled overwrite, object confusion, or information disclosure path. ## 5. One-sentence report phrase Incorrect legacy TX rate encoding in iwlwifi mvm can cause old Intel WiFi devices to receive invalid TX or beacon rate values, potentially triggering firmware assert or wireless availability loss, but no kernel memory corruption or privilege escalation primitive is indicated. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be auto-closed or handled as low priority unless the product specifically relies on affected old Intel WiFi hardware in security-sensitive deployments. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: iwlwifi: mvm: fix driver-set TX rates on old devices Commit: 6fe92651b44fd3cfc8dcfdaad0e82885c384dada Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6fe92651b44fd3cfc8dcfdaad0e82885c384dada Commit description: On old devices such as 7265D, rates are still encoded in version 1 format, which doesn't use the CCK/OFDM rate index (0-3/0-7) but rather their PLCP value (e.g. 10 for 1 Mbps CCK rate.) While introducing v3 rates, I changed the driver from internally handling v1 rates and converting to v2, to internally handling v3 and converting to v1 or v2 according to the firmware. I accordingly changed the code in iwl_mvm_mac80211_idx_to_hwrate() to no longer have different values for different APIs. This was correct. However, I later reverted this part of the change, because it was reported that I had broken beacon rates, causing a FW assert/crash. This caused TX_CMD rates to be set incorrectly, potentially causing a warning when reported back from the device as having been used. Fix this (hopefully correctly now) by handling beacon rates in the TX_CMD that's embedded in the beacon template command separately. Restore iwl_mvm_mac80211_idx_to_hwrate() to return only the rate index, not PLCP value, fixing the real TX_CMD. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg Link: https://patch.msgid.link/20260515151351.7407e293dff7.I4ea1a17f8fe99c933d3f3e30d077cf4246125c3e@changeid Signed-off-by: Miri Korenblit Signed-off-by: Greg Kroah-Hartman Changed files: drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c drivers/net/wireless/intel/iwlwifi/mvm/utils.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=6fe92651b44fd3cfc8dcfdaad0e82885c384dada ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64176 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64176 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:L/PR:H/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS score: 3.3 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: 0 Paranoid ActionableScore: 1 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).