From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-74413][MODERATE 7.0] wifi: rtw89: fix wrong pci_get_drvdata type in AER handlers [ Upstream Date: Sat, 15 Aug 2026 08:38:30 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-74413 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: aefc30e4a829c1683f6ae999df7f9310c27eae6c List-Id: CVE: CVE-2026-74413 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: rtw89: fix wrong pci_get_drvdata type in AER handlers [ Upstream Commit: aefc30e4a829c1683f6ae999df7f9310c27eae6c Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aefc30e4a829c1683f6ae999df7f9310c27eae6c Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74413 Analysis date: Sat, 15 Aug 2026 08:38:30 -0400 ActionableScore: 5 ActionableScore lower bound: 3 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: A type confusion in rtw89 PCI AER handlers caused an `ieee80211_hw` pointer to be treated as `net_device`, allowing wrong-offset kernel reads and writes during PCI error recovery, with realistic impact of local or device-mediated DoS and a weak manual-review concern for broader corruption impact. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74413 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74413 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 7.0 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-2026-74413 MODERATE CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';CWE-843;*CWE-787;CWE-704;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.8';DESCR 'rtw89 PCI AER handlers used pci_get_drvdata as if it returned a net_device pointer, while probe stored an ieee80211_hw pointer. As a result, netif_device_detach and netif_device_attach could read and write wrong offsets in the ieee80211_hw object during PCI error recovery. This is a type confusion and wrong-object access in kernel context, with a practical impact of driver state corruption or kernel crash. For the CVSS the PR:L is used for the paranoid score because some deployments may allow a reduced capability local actor, service account, or delegated recovery path to trigger PCI error recovery, while the normal base case is closer to PR:H. The issue is not directly network reachable and normally depends on PCIe AER injection, reset/error recovery control, or a real device fault. Impact is at least local denial of service via kernel crash, and in worst case may allow limited confidentiality or integrity impact due to kernel memory corruption and should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4) YES REMOTE DANGER SIMPLEFIX ERRORPATH NETWORK LINUS TEST DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=3 ## 1. ActionableScore * Conservative score: 3 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: This is not a strong Important candidate by itself, because the trigger path is PCI AER recovery and not directly reachable by ordinary local users or the network. However, it should not be auto-closed because the bug is a real kernel type confusion with wrong-offset reads/writes in a driver error-recovery path. ## 2. Signal breakdown Conservative signals: * Memory corruption, weak/indirect corruption candidate: +1 `pci_get_drvdata()` returns `ieee80211_hw`, but the old code treated it as `net_device`, so `netif_device_detach()` and `netif_device_attach()` accessed wrong offsets. * Reliable kernel crash / strong DoS: +1 Wrong-object access in kernel context can corrupt driver state or crash during PCI error recovery. * Privileged kernel/device-management memory corruption path: +1 The corruption occurs in PCI AER device-management handlers. * Requires admin/root/CAP_* in typical deployments: -2 Reliable triggering usually requires PCIe AER injection, reset/error recovery control, a test module, or equivalent privileged access. * Firmware-mediated external influence: +1 A real PCIe device or firmware/hardware error can invoke the AER path, even if this is not directly network-triggerable. Conservative total: 3 Paranoid additional interpretation: * Weak LPE concern: +1 The primitive is invalid struct interpretation with wrong-offset kernel writes. There is no demonstrated reclaim, arbitrary write, or callback control, but the corruption sink is nontrivial and deserves manual review. Paranoid total: 5 ## 3. Reachability analysis The bug is reached through PCI AER handlers in the Realtek rtw89 PCI WiFi driver. It is not directly network reachable and normal WiFi packet traffic is not sufficient based on the patch. In typical deployments, a local attacker would need privileged control over PCI error injection, device reset/error recovery, or a kernel module to trigger the handlers reliably. A real hardware or firmware-driven PCIe error could also reach the path, but that is not the same as a remote network trigger. Namespaces and containers generally do not make this directly reachable unless the container or service has delegated device-management privileges. Reduced-capability root or a service account with access to recovery/control paths should be treated as a paranoid PR:L-like scenario rather than full host-root. Call-site confidence: high. The affected handlers and the wrong API usage are shown directly in the patch. ## 4. Severity interpretation This behaves more like an actionable Moderate than an ordinary Moderate. The realistic impact is local or device-mediated DoS through driver/kernel state corruption during PCI error recovery. The theoretical memory corruption concern is higher than a simple NULL dereference because the old code passed an `ieee80211_hw` object to APIs expecting `net_device`, causing fixed wrong-offset reads and writes. There is no evidence of a strong LPE primitive such as attacker-controlled reclaim, arbitrary write, controlled object replacement, function-pointer control, or refcount takeover. Therefore it should not be rated as a strong Important candidate without further evidence. ## 5. One-sentence report phrase A type confusion in rtw89 PCI AER handlers caused an `ieee80211_hw` pointer to be treated as `net_device`, allowing wrong-offset kernel reads and writes during PCI error recovery, with realistic impact of local or device-mediated DoS and a weak manual-review concern for broader corruption impact. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: the bug is a real kernel type confusion with wrong-offset writes, not merely validation or bookkeeping. The trigger is constrained, but the corruption target and downstream effects should be reviewed manually before closure. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: rtw89: fix wrong pci_get_drvdata type in AER handlers [ Upstream Commit: aefc30e4a829c1683f6ae999df7f9310c27eae6c Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aefc30e4a829c1683f6ae999df7f9310c27eae6c Changed files: drivers/net/wireless/realtek/rtw89/pci.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=aefc30e4a829c1683f6ae999df7f9310c27eae6c ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74413 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74413 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS score: 5.8 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: 5 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 7.0 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).