From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-74326][LOW] wifi: mt76: mt7921: fix resource leak in probe error path [ Upstream Date: Sun, 16 Aug 2026 02:54:06 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-74326 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: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 79a307b2730e4b4e060cf3e19a6c21b87116ee78 List-Id: CVE: CVE-2026-74326 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: wifi: mt76: mt7921: fix resource leak in probe error path [ Upstream Commit: 79a307b2730e4b4e060cf3e19a6c21b87116ee78 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=79a307b2730e4b4e060cf3e19a6c21b87116ee78 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74326 Analysis date: Sun, 16 Aug 2026 02:54:06 -0400 ActionableScore: 0 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74326 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74326 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-2026-74326 LOW CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;CWE-404;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.1';DESCR 'The mt7921 PCI probe error path could return directly after pcim_iomap_region or devm_kmemdup failure while leaving an allocated mt76 device and PCI IRQ vectors behind. This is a resource leak in an initialization error path rather than a memory corruption primitive. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over PCI driver probe bind unbind or module handling, plus conditions that make the early allocation or mapping step fail. The issue is not network reachable and cannot be triggered by WiFi traffic alone. Impact is denial of service only through possible resource exhaustion after repeated failed probe attempts. No confidentiality or integrity impact is indicated by the bug class or patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0) SKIP CVE-2026-74326 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: ee5bb35d2b83fadc6920aa2478326fb50ea653a9 YES NO NO unknown MAYBE REMOTE INIT NOMEMCHK SIMPLEFIX LEAK ERRORPATH NETWORK LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 1. ActionableScore * Conservative score: 0 * Paranoid score: 0 * Final recommended bucket: **Ordinary Moderate / Low-like** 2. Signal breakdown * Availability impact realistic: +1 only in a very limited sense. Repeated failed probe attempts could leak mt76 device state and PCI IRQ vectors, but a single failure is not shown to cause immediate system-wide failure. * Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering normally requires control over PCI driver probing, bind/unbind, module handling, or fault-injection style failure conditions. * Hard or unreliable special condition: -1. The leak occurs only if `pcim_iomap_region()` or `devm_kmemdup()` fails after earlier allocations in the probe path. * No memory corruption signal. The patch fixes missed cleanup in an error path, not UAF, OOB access, double free, type confusion, or arbitrary write. * No confidentiality or integrity signal. The leaked objects are not shown to expose data or modify protected state. * No remote or firmware-mediated trigger. WiFi traffic does not reach this probe error path. 3. Reachability analysis The realistic trigger is local and privileged. An attacker would need the ability to influence PCI device probing or repeatedly bind, unbind, reload, or otherwise force the mt7921 PCI probe path to fail at the specific allocation or mapping points. Namespaces do not normally reduce this to an unprivileged trigger because PCI driver management is host-admin controlled. The affected driver is hardware-specific and the vulnerable path is an initialization error path, not a normal packet-processing or wireless data path. 4. Severity interpretation This behaves like a Low-like or ordinary Moderate resource leak, not an actionable Moderate or Important kernel vulnerability. The theoretical worst case is resource exhaustion after repeated privileged probe failures, but the patch does not support memory corruption, privilege escalation, information disclosure, or a network-triggerable attack. The issue should not be treated like a kernel memory lifetime bug despite involving leaked kernel resources. 5. One-sentence report phrase A cleanup bug in the mt7921 PCI probe error path can leak an allocated mt76 device and PCI IRQ vectors when early mapping or allocation fails, but triggering is privileged and the practical impact is limited to possible local resource exhaustion. 6. Manual review recommendation NO MANUAL CHECK NEEDED This is a privileged probe-path resource leak with no supported memory corruption primitive, no network reachability, and no plausible LPE or data exposure path. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mt76: mt7921: fix resource leak in probe error path [ Upstream Commit: 79a307b2730e4b4e060cf3e19a6c21b87116ee78 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=79a307b2730e4b4e060cf3e19a6c21b87116ee78 Changed files: drivers/net/wireless/mediatek/mt76/mt7921/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=79a307b2730e4b4e060cf3e19a6c21b87116ee78 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74326 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74326 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:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.1 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: unknown Paranoid ActionableScore: 0 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).