From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80666][LOW] Bluetooth: sco: Fix a race condition in sco_sock_timeout() [ Upstream Date: Fri, 28 Aug 2026 06:47:41 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80666 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: 2 X-AL-KERNEL-ActionableScore-Lower: 1 X-AL-KERNEL-Commit: da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce List-Id: CVE: CVE-2026-80666 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: Bluetooth: sco: Fix a race condition in sco_sock_timeout() [ Upstream Commit: da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80666 Analysis date: Fri, 28 Aug 2026 06:47:41 -0400 ActionableScore: 2 ActionableScore lower bound: 1 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-2026-80666 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80666 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-2026-80666 LOW 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:N/I:N/A:H';CWE-362;CWE-667;*CWE-833;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A race in Bluetooth SCO socket close handling can deadlock when sco_sock_close holds the socket lock while disable_delayed_work_sync waits for timeout_work, and sco_sock_timeout tries to take the same socket lock. A local process can trigger this by creating and closing an SCO socket while the asynchronous timeout work is active, causing a stalled close path and possible Bluetooth subsystem denial of service. For the CVSS the PR:L is used because a local process or user context is required to create and close the affected socket, even if no full administrator privileges are needed. The issue is not directly network reachable and the patch context supports a deadlock or stall rather than memory corruption. Impact is denial of service only, with no supported confidentiality or integrity impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) YES REMOTE LOCK DEADLOCK INIT RACE NETWORK TIMER HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=1 1. ActionableScore * Conservative score: 1 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like** 2. Signal breakdown * Local unprivileged trigger: +1. A local process can create and close an affected Bluetooth SCO socket, assuming Bluetooth SCO support is available. * Availability impact realistic: +1. The failure mode is a deadlock or stalled close path involving `lock_sock()` and `disable_delayed_work_sync()`, which can affect Bluetooth SCO availability. * Hard or unreliable race / special timing required: -1. The issue requires overlap between socket close and asynchronous timeout work. * Rare AND difficult-to-reach subsystem/configuration: -1 in the conservative score. Bluetooth SCO is not a universal/default server exposure and usually depends on Bluetooth support and relevant runtime setup. * Paranoid difference: omit the rare-subsystem penalty if the evaluated product commonly enables Bluetooth SCO or exposes it to local users. 3. Reachability analysis The bug is locally triggerable through Bluetooth SCO socket lifecycle operations. It is not directly network reachable in the CVSS sense because packet traffic alone does not trigger the vulnerable close path. Namespaces do not materially turn this into a remote issue, but product policy matters if unprivileged users are allowed to create Bluetooth sockets. The path is configuration and hardware dependent, and exploitation mainly requires winning a timing window between `sco_sock_close()` and `sco_sock_timeout()`. 4. Severity interpretation This behaves like a DoS-only locking bug, not an Important-class memory corruption issue. The patch fixes lock ordering and work cancellation placement, and the described failure is a circular locking dependency/deadlock. There is no supported UAF, OOB access, attacker-controlled reclaim, arbitrary write, callback hijack, or credential/security-boundary primitive. Realistic impact is Bluetooth subsystem stall or local availability degradation rather than privilege escalation. 5. One-sentence report phrase A race in Bluetooth SCO socket close handling can deadlock `sco_sock_close()` against asynchronous `sco_sock_timeout()` work, allowing a local user to cause a Bluetooth SCO denial of service under timing-dependent conditions. 6. Manual review recommendation NO MANUAL CHECK NEEDED. This is suitable for automatic low-priority handling because the patch and trace support a deadlock/stall only, with no memory corruption or privilege-escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: Bluetooth: sco: Fix a race condition in sco_sock_timeout() [ Upstream Commit: da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce Changed files: include/linux/rcupdate.h kernel/workqueue.c include/net/sock.h net/bluetooth/sco.c kernel/locking/lockdep.c net/core/sock.c kernel/kthread.c arch/x86/kernel/process.c arch/x86/entry/entry_64.S include/linux/kref.h net/socket.c fs/file_table.c fs/open.c arch/x86/entry/common.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=da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80666 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80666 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:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.7 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: 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).