From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-46302][LOW] selinux: allow multiple opens of /sys/fs/selinux/policy Date: Mon, 08 Jun 2026 14:55:09 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-46302 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: unknown X-AL-KERNEL-Commit: 714362f3779dfa453a78ced32396a72726962a41 List-Id: CVE: CVE-2026-46302 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: selinux: allow multiple opens of /sys/fs/selinux/policy Commit: 714362f3779dfa453a78ced32396a72726962a41 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=714362f3779dfa453a78ced32396a72726962a41 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46302 Analysis date: Mon, 08 Jun 2026 14:55:09 -0400 ActionableScore: 2 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-2026-46302 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46302 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-2026-46302 LOW CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-667;**CWE-400;CWE-284;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'SELinux /sys/fs/selinux/policy allowed only one open at a time through the policy_opened state. A local process that is allowed to read the kernel policy could open the policy file and keep it open, causing later readers to receive EBUSY and preventing other tools from reading the active SELinux policy. For the CVSS the PR:L is used because the attacker needs local execution and SELinux permission to read_policy, but not full administrative control in deployments where this permission is delegated to service or confined domains. The issue is not network reachable and does not indicate memory corruption or a privilege escalation primitive. Impact is denial of service against policy inspection and management workflows, with possible disruption of security tooling that depends on reading the live policy.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) MAYBE LOCK DANGER DISK NOMEMCHK SIMPLEFIX LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 1. ActionableScore * Conservative score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: 2. Signal breakdown * Availability impact realistic: +1. A process can keep `/sys/fs/selinux/policy` open and block other readers with `EBUSY`. * Broad/default/common subsystem: +1. SELinux is common on major distributions, but the affected interface is only present and relevant when SELinux is enabled. * No remote reachability: +0. The trigger is local file open behavior, not packet or network input. * No memory corruption: +0. The patch removes an exclusive-open flag and BUG_ONs, but does not indicate UAF, OOB write, double-free, or object lifetime corruption. * No privilege escalation plausible: +0. The bug blocks policy reads but does not grant new SELinux permissions or expose privileged objects. 3. Reachability analysis A local process that passes the SELinux `read_policy` permission check can open `/sys/fs/selinux/policy` and keep the descriptor open, preventing other processes from reading the active kernel policy. This is not generally reachable by arbitrary unprivileged users unless the active SELinux policy delegates `read_policy` to their domain. Containers do not normally make this easier because SELinux is not a per-container security namespace in the same way as common Linux namespaces. The affected path is available on SELinux-enabled systems, but realistic abuse requires a permitted local domain and causes a limited denial of service against policy inspection or security tooling. 4. Severity interpretation This behaves like an ordinary Moderate or Low-like local denial of service, not an Important-class kernel vulnerability. The theoretical impact is blocking access to the live SELinux policy file for other readers. Realistic exploitation evidence supports availability impact against management and inspection workflows, but not kernel crash, memory corruption, information disclosure, sensitive file descriptor theft, or privilege escalation. 5. One-sentence report phrase A local process with SELinux read_policy permission can keep /sys/fs/selinux/policy open and block other policy readers, causing a limited denial of service against SELinux policy inspection tools. 6. Manual review recommendation NO MANUAL CHECK NEEDED. This is a local logic DoS with no memory corruption, no network reachability, no privilege escalation evidence, and limited availability impact. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: selinux: allow multiple opens of /sys/fs/selinux/policy Commit: 714362f3779dfa453a78ced32396a72726962a41 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=714362f3779dfa453a78ced32396a72726962a41 Commit description: Currently there can only be a single open of /sys/fs/selinux/policy at any time. This allows any process to block any other process from reading the kernel policy. The original motivation seems to have been a mix of preventing an inconsistent view of the policy size and preventing userspace from allocating kernel memory without bound, but this is arguably equally bad. Eliminate the policy_opened flag and shrink the critical section that the policy mutex is held. While we are making changes here, drop a couple of extraneous BUG_ONs. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/selinux/20100726193414.19538.64028.stgit@paris.rdu.redhat.com/ Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman Changed files: security/selinux/selinuxfs.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=714362f3779dfa453a78ced32396a72726962a41 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46302 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46302 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:L/PR:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.5 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: 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).