From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80830][MODERATE 7.0] usb: core: Add lock to usb_wakeup_notification() Date: Fri, 04 Sep 2026 17:55:21 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80830 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: a7a16167991c88016acef720927400404039d850 List-Id: CVE: CVE-2026-80830 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: usb: core: Add lock to usb_wakeup_notification() Commit: a7a16167991c88016acef720927400404039d850 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a7a16167991c88016acef720927400404039d850 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80830 Analysis date: Fri, 04 Sep 2026 17:55:21 -0400 ActionableScore: 5 ActionableScore lower bound: 2 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80830 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80830 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-2026-80830 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80830 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-362;CWE-667;Other CVSS 'AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '6.4';DESCR 'A race in usb_wakeup_notification() can occur because the function accessed USB hub state without device_state_lock while hub_disconnect() uses that lock to protect teardown. The xHCI driver can call this path from IRQ context, so a wakeup notification may run concurrently with hub disconnect and dereference freed hub or port memory. For the CVSS the PR:N is used for the paranoid score because a malicious or controlled USB device can potentially trigger the hardware event without needing an account on the target system, although physical access to the USB bus is still required. The issue is not network reachable. Impact is at least denial of service via kernel crash, and in the worst still defensible interpretation it may allow confidentiality or integrity impact because this is a race based use after free candidate involving access to freed kernel objects.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4) YES LOCK DANGER USB RACE UAF HARDWARE LINUS KPANIC NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=2 1. ActionableScore * Conservative score: 2 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: 2. Signal breakdown * Memory corruption, weak/indirect corruption candidate: +1. The patch explicitly prevents dereferencing freed memory, but no controlled reclaim or object replacement is shown. * Real lifetime corruption: +1. This is a race between `usb_wakeup_notification()` and `hub_disconnect()` over USB hub lifetime/state. * Reliable kernel crash / strong DoS: +1. A freed hub/port pointer dereference from IRQ context is a realistic crash path. * Broad/default/common subsystem: +1. USB core and xHCI are common on affected systems. * Weak LPE concern: +1 in paranoid scoring only. The code can write through stale hub state via `set_bit(portnum, hub->wakeup_bits)`, but no attacker-controlled reclaim primitive is demonstrated. * Confidentiality impact plausible: +1 in paranoid scoring only. UAF on freed kernel objects can theoretically expose stale object state, but this is not demonstrated. * Integrity impact plausible: +1 in paranoid scoring only. The stale `set_bit()` write makes limited freed-object corruption plausible, but not a proven arbitrary write. * Hard or unreliable race / special timing required: -1. The issue depends on an IRQ wakeup notification racing with hub disconnect. * Physical-only or rare hardware-only condition: -2. A practical unprivileged attack likely needs a malicious or controlled USB device or physical USB-bus influence, not a network path. 3. Reachability analysis The most plausible trigger is a USB wakeup event from xHCI racing with hub removal or disconnect. No local account is necessarily required if the attacker controls a USB device, but physical access or device-level influence is required. Namespaces and containers do not materially improve reachability because the vulnerable path is in USB core hardware event handling, not a namespaced user API. USB/xHCI is broadly deployed, but exploitation requires tight timing and specific hardware events. 4. Severity interpretation This is not an ordinary correctness fix because the commit explicitly mentions dereferencing freed memory and the patch serializes against `hub_disconnect()`. Realistic impact is most likely local/physical DoS through kernel crash. Theoretical impact can be higher because the stale object access includes a write to hub state, but the patch does not show controlled reclaim, callback control, type confusion, or arbitrary write. Therefore it is best treated as Actionable Moderate, not a clear Important-class issue. 5. One-sentence report phrase A race in `usb_wakeup_notification()` can allow an xHCI IRQ wakeup path to access USB hub state concurrently with `hub_disconnect()`, causing freed-memory dereference and likely kernel crash, with limited but nonzero UAF-based corruption concern under a malicious or controlled USB device scenario. 6. Manual review recommendation MANUAL CHECK REQUIRED. The bug is a race-based freed-memory dereference in USB core with a possible stale write through `hub->wakeup_bits`, so it should not be auto-closed even though realistic exploitation is constrained by physical access and timing. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: usb: core: Add lock to usb_wakeup_notification() Commit: a7a16167991c88016acef720927400404039d850 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a7a16167991c88016acef720927400404039d850 Commit description: Add a spin lock to usb_wakeup notification to prevent a race condition with dereferencing freed memory. This could be hit by the xHCI driver as it calls this function from an IRQ and could race with the hub_disconnect() function, which properly grabs this lock to protect the state of the device. Assisted-by: gkh_clanker_t1000 Signed-off-by: Griffin Kroah-Hartman Link: https://patch.msgid.link/20260713-usb_core_patches_1-v1-3-7721c2b33f53@kroah.com Signed-off-by: Greg Kroah-Hartman Changed files: drivers/usb/core/hub.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=a7a16167991c88016acef720927400404039d850 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80830 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80830 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:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 6.4 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: 2 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: YES 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).