From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-45922][LOW] RDMA/mlx5: Fix memory leak in GET_DATA_DIRECT_SYSFS_PATH handler [ Upstream Date: Wed, 27 May 2026 21:16:09 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-45922 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: 1 X-AL-KERNEL-Commit: ee998cdbff6680891b0efd9d6ce53a388e5342c3 List-Id: CVE: CVE-2026-45922 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: RDMA/mlx5: Fix memory leak in GET_DATA_DIRECT_SYSFS_PATH handler [ Upstream Commit: ee998cdbff6680891b0efd9d6ce53a388e5342c3 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ee998cdbff6680891b0efd9d6ce53a388e5342c3 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45922 Analysis date: Wed, 27 May 2026 21:16:09 -0400 ActionableScore: 2 ActionableScore lower bound: 1 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A local mlx5 RDMA uverbs caller can trigger a GET_DATA_DIRECT_SYSFS_PATH ENOSPC error path that leaks a kobject_get_path allocation, potentially causing limited resource-exhaustion DoS after repeated calls. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45922 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45922 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-2026-45922 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-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'The mlx5 RDMA uverbs GET_DATA_DIRECT_SYSFS_PATH handler can leak the kobject_get_path allocation when the device path is larger than the user output buffer and the ioctl returns ENOSPC. A local user or service with access to the affected RDMA uverbs device could repeatedly request the path with an undersized buffer and accumulate kernel memory leaks. For the CVSS the PR:L is used because triggering requires local access to the RDMA uverbs interface, but not necessarily full administrator privileges when the device node is delegated to users or RDMA workloads. The issue is not network reachable. Impact is limited to availability through resource exhaustion. No supported evidence indicates information disclosure, integrity impact, kernel memory corruption, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) MAYBE SIMPLEFIX LEAK ERRORPATH NETWORK HARDWARE LINUS TEST INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=1 ## 1. ActionableScore * Conservative score: 1 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown * Local trigger with RDMA uverbs access: +1 A local user or service with access to the affected mlx5 RDMA uverbs device can call the GET_DATA_DIRECT_SYSFS_PATH handler with an undersized output buffer. * Availability impact realistic: +1 in paranoid scoring Repeated calls can leak kernel memory and may eventually cause resource exhaustion, but a single call only leaks a small allocation. * Rare or configuration-dependent subsystem: -1 conservative The issue requires mlx5 RDMA hardware, the relevant uverbs method, and device node access. It is not a default generic syscall path. * No generic memory corruption: +0 The bug is a missing kfree() on an ENOSPC error path, not UAF, double-free, OOB write, heap overwrite, or arbitrary write. * No privilege escalation or confidentiality impact: +0 The patch does not indicate information disclosure, integrity impact, credential exposure, or LPE. ## 3. Reachability analysis The bug is locally reachable by processes that can access the mlx5 RDMA uverbs interface. In many systems this access is limited to RDMA-capable workloads, device groups, containers with passed-through RDMA devices, or trusted HPC/cloud tenants. Namespaces and containers can matter if RDMA devices are delegated to untrusted workloads, but the issue is still local and not network-triggered by RDMA traffic alone. Realistic exploitation is repeated local ioctl abuse with an undersized output buffer to accumulate memory leaks. It is not a remote attack path and does not provide a memory corruption primitive. ## 4. Severity interpretation This behaves like ordinary Moderate or Low-like resource exhaustion. The theoretical impact is local DoS through accumulated kernel memory leakage. Realistic exploitation requires access to a specific RDMA device interface and repeated calls. There is no evidence of kernel memory corruption, privilege escalation, or sensitive data exposure. ## 5. One-sentence report phrase A local mlx5 RDMA uverbs caller can trigger a GET_DATA_DIRECT_SYSFS_PATH ENOSPC error path that leaks a kobject_get_path allocation, potentially causing limited resource-exhaustion DoS after repeated calls. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This is a hardware-specific local memory leak with no demonstrated memory corruption, privilege escalation, information disclosure, or network reachability. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: RDMA/mlx5: Fix memory leak in GET_DATA_DIRECT_SYSFS_PATH handler [ Upstream Commit: ee998cdbff6680891b0efd9d6ce53a388e5342c3 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ee998cdbff6680891b0efd9d6ce53a388e5342c3 Changed files: drivers/infiniband/hw/mlx5/std_types.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=ee998cdbff6680891b0efd9d6ce53a388e5342c3 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45922 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45922 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: 1 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).