From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64110][LOW] igc: fix potential skb leak in igc_fpe_xmit_smd_frame() Date: Sun, 19 Jul 2026 21:09:29 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64110 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: f1bafd35f11b3aca1c7bb38da173b8787364a04c List-Id: CVE: CVE-2026-64110 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: igc: fix potential skb leak in igc_fpe_xmit_smd_frame() Commit: f1bafd35f11b3aca1c7bb38da173b8787364a04c Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f1bafd35f11b3aca1c7bb38da173b8787364a04c Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64110 Analysis date: Sun, 19 Jul 2026 21:09:29 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: An skb leak in igc_fpe_xmit_smd_frame() can occur when FPE verification descriptor initialization fails, causing local privileged resource exhaustion risk on affected igc devices, but no memory corruption or privilege escalation primitive is evident. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64110 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64110 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-2026-64110 LOW CHECK WITH IMPACT FROM ORIG NN IMPORTANT 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-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A memory leak in igc_fpe_xmit_smd_frame() can occur when an skb is allocated for a frame preemption verification SMD frame and igc_fpe_init_tx_descriptor() fails before ownership is transferred to the TX path. Repeated failures can leak skb objects and may eventually cause resource exhaustion or network driver degradation. For the CVSS the PR:L is used in the paranoid view because a reduced capability administrator, container root, or service account with delegated network device control could potentially enable or exercise the MAC Merge verification path. The issue is not directly network reachable and requires local control of the affected interface configuration plus a failing descriptor initialization path. Impact is denial of service through memory leakage only, with no evidence of memory corruption, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) YES REMOTE INIT SIMPLEFIX LEAK ERRORPATH NETWORK SKB LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 YES 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 Conservative signals: * Availability impact realistic: +1 Repeated skb leaks could eventually cause memory pressure or driver degradation. * Requires admin/root/CAP_NET_ADMIN in typical deployments: -2 The trigger path is via MAC Merge / FPE configuration, typically controlled through ethtool and requiring CAP_NET_ADMIN. * Rare AND difficult-to-reach subsystem/configuration: -1 Requires an affected Intel igc device, FPE/MM support, verification enabled, and the descriptor initialization failure path. * Hard or unreliable trigger condition: -1 The reproducer used fault injection to force igc_fpe_init_tx_descriptor() failure. Paranoid adjustment: * Treat repeated delegated network-device control as a possible sustained resource-exhaustion path. This raises practical concern slightly, but still not to Actionable Moderate. No added signals: * No memory corruption primitive. This is an skb leak, not UAF, double-free, OOB write, or type confusion. * No privilege escalation plausible from the patch. * No remote/network-triggerable path. Packet traffic alone does not appear to reach the failing allocation ownership path. * No confidentiality or integrity impact. Call-site confidence: high. The relevant caller chain is shown in the commit message and the patched function directly frees the leaked skb on the error path. ## 3. Reachability analysis The bug is reachable through the igc Frame Preemption / MAC Merge verification path, with the shown trigger using ethtool configuration. In normal deployments this requires local administrative network-device control, usually CAP_NET_ADMIN. A container or service with delegated control over the physical interface could lower the practical privilege barrier, but this is still not a normal unprivileged local trigger. The affected path is hardware and feature dependent. It requires an Intel igc adapter with the relevant FPE/MM support and a failure in igc_fpe_init_tx_descriptor(). The commit explicitly mentions fault injection to exercise the error path, so reliable real-world triggering is not demonstrated. ## 4. Severity interpretation This behaves like a low-end Moderate or Low-like resource leak. The realistic impact is memory consumption or network-driver degradation after repeated failures. It does not look like an Important-class kernel vulnerability because the patch does not show memory corruption, object lifetime reuse, attacker-controlled reclaim, arbitrary write, page-cache corruption, sensitive object access, or a security-boundary bypass. The paranoid score stays low because even assuming delegated CAP_NET_ADMIN and repeated triggering, the impact remains DoS by leak only. ## 5. One-sentence report phrase An skb leak in igc_fpe_xmit_smd_frame() can occur when FPE verification descriptor initialization fails, causing local privileged resource exhaustion risk on affected igc devices, but no memory corruption or privilege escalation primitive is evident. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be auto-closed for urgent triage purposes because it is a privileged, hardware/feature-dependent skb leak with no evidence of memory corruption, remote reachability, confidentiality impact, integrity impact, or privilege escalation. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: igc: fix potential skb leak in igc_fpe_xmit_smd_frame() Commit: f1bafd35f11b3aca1c7bb38da173b8787364a04c Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f1bafd35f11b3aca1c7bb38da173b8787364a04c Commit description: When igc_fpe_init_tx_descriptor() fails, no one takes care of an allocated skb, leaking it. [1] Use dev_kfree_skb_any() on failure. Tested on an I226 adapter with the following command, while injecting faults in igc_fpe_init_tx_descriptor() to trigger the error path. # ethtool --set-mm $DEV verify-enabled on tx-enabled on pmac-enabled on [1] unreferenced object 0xffff888113c6cdc0 (size 224): ... backtrace (crc be3d3fda): kmem_cache_alloc_node_noprof+0x3b1/0x410 __alloc_skb+0xde/0x830 igc_fpe_xmit_smd_frame.isra.0+0xad/0x1b0 igc_fpe_send_mpacket+0x37/0x90 ethtool_mmsv_verify_timer+0x15e/0x300 Cc: stable@vger.kernel.org Fixes: 5422570 ("igc: add support for frame preemption verification") Signed-off-by: Kohei Enju Reviewed-by: Simon Horman Reviewed-by: Faizal Rahim Tested-by: Avigail Dahan Signed-off-by: Tony Nguyen Link: https://patch.msgid.link/20260515182419.1597859-10-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Changed files: drivers/net/ethernet/intel/igc/igc_tsn.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=f1bafd35f11b3aca1c7bb38da173b8787364a04c ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64110 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64110 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).