From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80744][LOW] netfilter: nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort path [ Upstream Date: Thu, 03 Sep 2026 05:06:47 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80744 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: 1 X-AL-KERNEL-ActionableScore-Lower: 0 X-AL-KERNEL-Commit: 2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 List-Id: CVE: CVE-2026-80744 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: netfilter: nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort path [ Upstream Commit: 2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80744 Analysis date: Thu, 03 Sep 2026 05:06:47 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: nf_tables_offload may emit WARN_ON_ONCE for an expected ENOMEM rollback failure during nftables offload transaction processing, which can cause local DoS only on systems where warnings are fatal or operationally disruptive. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80744 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80744 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-2026-80744 LOW https://www.kernelcve.org/list/?q=CVE-2026-80744 CHECK WITH IMPACT FROM ORIG NN LOW 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-703;CWE-754;CWE-755;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'nf_tables_offload can emit a WARN_ON_ONCE during transaction rollback when ndo_setup_tc or flow block callback allocation fails with ENOMEM. This is an expected low memory error path rather than evidence of memory corruption, but on systems configured with panic_on_warn it can turn a controlled allocation failure during nftables offload updates into a local denial of service. For the CVSS the PR:L is used in the paranoid score because a reduced capability root, container root, or service account with CAP_NET_ADMIN may be able to submit nftables offload changes without full host administrator privileges. The issue is not directly network reachable and is triggered through local netlink control plane operations, not by packet traffic. Impact is limited to availability through warning induced panic or operational disruption, with no supported confidentiality or integrity impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) YES REMOTE NOMEMCHK NETFILTER LEAK HARDWARE NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Triggered signals: * Reliable kernel crash / strong DoS: +1 in paranoid only. The WARN_ON_ONCE can become a host crash only on systems configured with panic_on_warn, or similar warning-fatal policy. * Requires admin/root/CAP_NET_ADMIN in typical deployments: -2. Triggering requires nftables offload transaction updates through the local netlink control plane, normally gated by CAP_NET_ADMIN. * Hard or unreliable condition: -1. The demonstrated path depends on ENOMEM during rollback, reproduced under memory pressure or fault injection. * Rare AND difficult-to-reach subsystem/configuration: -1. This is nf_tables offload rollback, not the normal packet-processing path. Not awarded: * No remote/network-triggerable score. Packet traffic does not directly trigger this path. * No memory corruption score. The patch suppresses an expected ENOMEM warning and does not show UAF, OOB, double-free, stale pointer reuse, or arbitrary write. * No confidentiality or integrity score. There is no supported leak, write primitive, or privilege escalation path. ## 3. Reachability analysis The bug is triggered locally through nf_tables offload rule transaction handling, not by receiving packets. In normal deployments, creating or updating these rules requires CAP_NET_ADMIN. Namespace or container setups may reduce the practical privilege barrier if a container root or service account has delegated CAP_NET_ADMIN, but this still is not an unprivileged local trigger. Realistic impact requires memory pressure or allocation failure in the rollback path, and a severe outcome generally requires panic_on_warn or equivalent policy. Call-site confidence: high, because the stack trace and affected abort path are provided. ## 4. Severity interpretation This behaves like a low-end Moderate or Low-like DoS-only issue. The concrete failure is a warning on an expected ENOMEM condition during rollback. There is no evidence of memory corruption, privilege escalation, information disclosure, or packet-triggered remote attack. The paranoid score keeps a small actionability signal because panic_on_warn can convert the warning into a kernel panic, but it should not be treated as Important-class. ## 5. One-sentence report phrase nf_tables_offload may emit WARN_ON_ONCE for an expected ENOMEM rollback failure during nftables offload transaction processing, which can cause local DoS only on systems where warnings are fatal or operationally disruptive. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be autoclosable for security triage in most environments because it is WARN/ENOMEM handling, requires privileged local control-plane access, and has no demonstrated memory corruption or privilege escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: netfilter: nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort path [ Upstream Commit: 2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 Changed files: net/netfilter/nf_tables_offload.c net/netfilter/nf_tables_api.c net/netfilter/nfnetlink.c net/netlink/af_netlink.c net/netfilter/af_netlink.c net/socket.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=2319033c4bf8bdb275a9e4e1f7af9bf8a457ad79 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80744 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80744 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: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: 0 Paranoid ActionableScore: 1 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).