From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80613][MODERATE 7.0] veth: fix NAPI leak in XDP enable error path [ Upstream Date: Fri, 28 Aug 2026 04:45:20 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80613 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: 7 X-AL-KERNEL-ActionableScore-Lower: 4 X-AL-KERNEL-Commit: fc51373345e7e6ea73da2650cb497309c50b077a List-Id: CVE: CVE-2026-80613 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: veth: fix NAPI leak in XDP enable error path [ Upstream Commit: fc51373345e7e6ea73da2650cb497309c50b077a Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc51373345e7e6ea73da2650cb497309c50b077a Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80613 Analysis date: Fri, 28 Aug 2026 04:45:20 -0400 ActionableScore: 7 ActionableScore lower bound: 4 Actionable bucket: Strong Important candidate / Actionable Moderate at minimum Manual review required: YES Summary: A veth XDP enable rollback bug can leave a stale NAPI object linked after partial initialization failure, causing later device teardown to access or corrupt freed queue memory and potentially resulting in a local kernel crash or UAF-based privilege escalation concern. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80613 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80613 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-2026-80613 MODERATE 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:H/I:H/A:H';*CWE-416;CWE-459;*CWE-672;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A use after free can occur in the veth XDP enable error path because netif_napi_add can succeed for a queue but the later xdp_rxq_info registration step can fail. The rollback loop decrements the index before its first iteration and can skip netif_napi_del for the failed queue, leaving a stale napi_struct linked in the device NAPI list. When the veth device is later destroyed, the queue memory containing that NAPI object can be freed and reused, while later NAPI list traversal may access or corrupt the reallocated memory. For the CVSS the PR:L is used because reliable triggering normally requires local ability to configure veth and XDP, such as CAP_NET_ADMIN or delegated network administration inside a namespace or container. The issue is not directly network reachable and is triggered through local control plane configuration, not by packet traffic. Impact is at least local denial of service via kernel crash and in the paranoid case may allow confidentiality or integrity impact because the patch context describes a real UAF with memory corruption risk.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 6) YES LEAK ERRORPATH UAF NETWORK HARDWARE KPANIC KPANIC INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN6 DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=7 ActionableScoreLower=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 7 * Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum** ## 2. Signal breakdown Conservative signals: * Memory corruption, Strong corruption primitive: +2. The commit explicitly describes a dangling `napi_struct` left in the device NAPI list and later UAF when freed queue memory is reused. * Real lifetime corruption: +1. This is a stale lifetime/list membership bug involving `netif_napi_add()` without matching `netif_napi_del()`. * Reliable kernel crash / strong DoS: +1. Later device teardown can traverse the stale NAPI list entry and corrupt reused memory. * Hard or special trigger condition: -1. The bug requires the XDP enable error path, specifically failure after `netif_napi_add()` but before full queue setup. * Requires CAP_NET_ADMIN/CAP_BPF or equivalent in typical deployments: -2. Reliable triggering normally requires veth/XDP configuration privileges. Paranoid additional signals: * Local low-privilege or delegated namespace trigger: +1. In container or user namespace setups, CAP_NET_ADMIN may be delegated and should not always be treated as full host root. * Privilege escalation plausible: +2. The UAF includes stale list traversal and corruption of reallocated memory, which is stronger than a plain NULL dereference or read-only stale pointer. * Broad container networking exposure: +1. veth is common in container networking, although XDP attachment is not always available to untrusted users. ## 3. Reachability analysis The bug is locally reachable through veth XDP configuration and the rollback path in `veth_enable_xdp_range()`. In a typical host configuration, this requires administrative networking privileges and possibly privileged BPF/XDP access, so the conservative score applies the CAP penalty. In containerized environments or systems with delegated network administration, a reduced-privilege root or service account may be able to exercise the path without being equivalent to full host root. The issue is not directly network reachable and is not triggered by packet traffic alone. Call-site confidence: high. The supplied patch and commit message describe the relevant add, rollback, teardown, stale list, reuse, and UAF sequence directly. ## 4. Severity interpretation This should not be treated as an ordinary Moderate cleanup bug. The realistic demonstrated impact is local DoS or memory corruption during teardown after a failed XDP enable path. The theoretical higher-risk concern is that stale NAPI list traversal can touch memory after the containing veth queue has been freed and reused, which makes privilege escalation plausible enough for manual review, although no controlled reclaim or working LPE primitive is demonstrated in the patch text. ## 5. One-sentence report phrase A veth XDP enable rollback bug can leave a stale NAPI object linked after partial initialization failure, causing later device teardown to access or corrupt freed queue memory and potentially resulting in a local kernel crash or UAF-based privilege escalation concern. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: the patch explicitly describes UAF and corruption of reallocated memory, and the practical risk depends on whether veth/XDP configuration is reachable by reduced-privilege container or namespace users in the evaluated product. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: veth: fix NAPI leak in XDP enable error path [ Upstream Commit: fc51373345e7e6ea73da2650cb497309c50b077a Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc51373345e7e6ea73da2650cb497309c50b077a Changed files: drivers/net/veth.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=fc51373345e7e6ea73da2650cb497309c50b077a ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80613 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80613 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:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 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: 4 Paranoid ActionableScore: 7 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).