From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80761][MODERATE REGULAR] Bluetooth: ISO: zero the sockaddr before returning it in getname Date: Fri, 04 Sep 2026 15:05:01 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80761 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 2 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 1f6d1f2611af0eb36b133a41d29ffd2cc2601615 List-Id: CVE: CVE-2026-80761 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: Bluetooth: ISO: zero the sockaddr before returning it in getname Commit: 1f6d1f2611af0eb36b133a41d29ffd2cc2601615 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1f6d1f2611af0eb36b133a41d29ffd2cc2601615 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80761 Analysis date: Fri, 04 Sep 2026 15:05:01 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like, but manual review recommended for kernel stack information leak Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80761 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80761 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 REGULAR 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-2026-80761 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80761 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N';*CWE-200;CWE-201;CWE-908;BEST CVSS score: '3.3';DESCR 'Bluetooth ISO getname can copy partially uninitialized sockaddr data from the kernel stack to user space. A local unprivileged process can reach the basic pad byte leak with getsockname on a BTPROTO_ISO socket, while the larger broadcast peer leak requires an established BIS or PA related connection state. For the CVSS the PR:L is used because a local user process is required to create or operate the socket, but no administrative privileges are needed for the basic leak path. The issue is not directly network reachable in the CVSS sense. Impact is limited confidentiality loss from a small kernel stack information leak, with no direct integrity impact, denial of service, or privilege escalation primitive shown by the code change.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like, but manual review recommended for kernel stack information leak (with actual score 2) YES REMOTE LEAK NETWORK LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 1. ActionableScore * Conservative score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like, but manual review recommended for kernel stack information leak** 2. Signal breakdown * Local unprivileged trigger: +1. A local unprivileged process can open a BTPROTO_ISO socket and reach the basic getsockname leak. * Confidentiality impact plausible: +1. The bug copies uninitialized kernel stack bytes to userspace. * No generic memory corruption: +0. The patch only initializes sockaddr output buffers and does not show UAF, OOB write, double free, type confusion, or refcount misuse. * No reliable kernel crash / strong DoS: +0. The described impact is disclosure, not panic or resource exhaustion. * No privilege escalation plausible: +0. The leak is small and bounded, with no demonstrated exploit chain or control primitive. * Rare subsystem penalty: +0. Bluetooth ISO is not universal, but the basic path is an ordinary local socket interface when the feature is enabled, so I would not subtract by default. 3. Reachability analysis A local user can trigger the basic one byte pad leak through getsockname on a BTPROTO_ISO socket if Bluetooth ISO support is available. The larger broadcast peer leak requires an established BIS or PA related connection state, which makes that path more environment dependent. This is not network reachable in the CVSS or ActionableScore sense because the attacker needs local code execution on the target. Namespaces do not meaningfully turn this into a remote issue, but local container or sandbox access may still matter if Bluetooth sockets are exposed. 4. Severity interpretation This behaves like a low severity local information disclosure rather than an actionable Moderate or Important kernel vulnerability. The theoretical value is that kernel stack leaks can sometimes help other exploit chains, but the demonstrated primitive here is only a small bounded disclosure from sockaddr padding and broadcast sockaddr fields. There is no evidence of memory corruption, write primitive, kernel crash, privilege escalation, or cross-boundary object ownership violation. 5. One-sentence report phrase Bluetooth ISO getname can disclose a small amount of uninitialized kernel stack data to a local unprivileged user through getsockname or getpeername, with limited confidentiality impact and no supported integrity, availability, or privilege escalation primitive. 6. Manual review recommendation YES REQUIRES MANUAL CHECK. Manual check is recommended because this is a kernel stack information leak reachable by a local unprivileged user, even though the ActionableScore remains low and the available evidence does not support Important severity. Call-site confidence: high, because the commit describes the do_getsockname copy path and the patch directly shows the missing memset in iso_sock_getname. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: Bluetooth: ISO: zero the sockaddr before returning it in getname Commit: 1f6d1f2611af0eb36b133a41d29ffd2cc2601615 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1f6d1f2611af0eb36b133a41d29ffd2cc2601615 Commit description: iso_sock_getname() fills a struct sockaddr_iso in place and returns its size without clearing it first, so bytes it does not write are copied to user space from the kernel stack. The getsockname(2) and getpeername(2) paths both run through do_getsockname(), which hands getname() an uninitialized sockaddr_storage on the stack and copies back up to the number of bytes getname() returns, so the driver has to initialize every byte it accounts for. Two ranges are left uninitialized: - struct sockaddr_iso is 10 bytes but only 9 are written (family, iso_bdaddr, iso_bdaddr_type), leaking the trailing pad byte on every call. - for a broadcast peer (BIS_LINK or PA_LINK) the returned length grows by sizeof(struct sockaddr_iso_bc), but only bc_sid, bc_num_bis and bc_bis are filled; bc_bdaddr and bc_bdaddr_type, the first 7 bytes of that structure, are never written. An unprivileged process can open a BTPROTO_ISO socket and reach the pad leak with getsockname(); the broadcast leak needs an established BIS/PA connection. l2cap and rfcomm already memset their sockaddr in getname for the same reason; do the same here. Fixes: ccf74f2 ("Bluetooth: Add BTPROTO_ISO socket type") Fixes: 0a766a0 ("Bluetooth: ISO: Fix getpeername not returning sockaddr_iso_bc fields") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman Changed files: net/bluetooth/iso.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=1f6d1f2611af0eb36b133a41d29ffd2cc2601615 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80761 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80761 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: Not available The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N 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: unknown 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: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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).