From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-46325][MODERATE 7.0] RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE [ Upstream Date: Tue, 09 Jun 2026 09:40:42 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-46325 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: 5 X-AL-KERNEL-ActionableScore-Lower: 4 X-AL-KERNEL-Commit: 409c2c5508f3d30627bea576f8676de523cb906e List-Id: CVE: CVE-2026-46325 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE [ Upstream Commit: 409c2c5508f3d30627bea576f8676de523cb906e Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=409c2c5508f3d30627bea576f8676de523cb906e Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46325 Analysis date: Tue, 09 Jun 2026 09:40:42 -0400 ActionableScore: 5 ActionableScore lower bound: 4 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: RDMA/rxe may translate an MR IOVA to the wrong virtual address when the MR page size differs from PAGE_SIZE, allowing local RDMA users or RDMA-adjacent peers with access to exposed queues and keys to cause unintended memory access and possible kernel panic. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46325 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46325 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-2026-46325 MODERATE CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H';CWE-682;CWE-823;CWE-119;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '6.4';DESCR 'RDMA/rxe can translate an IOVA to the wrong virtual address when the MR page size is not the same as the system PAGE_SIZE. The old mapping logic can select an incorrect struct page or an incorrect offset inside the system page because MR page indexing and stored PAGE_SIZE pages do not match. This can cause RDMA READ or WRITE operations to access unintended memory within the registered mapping and can lead to data corruption, limited information exposure, or a kernel panic. For the CVSS the PR:N is used in the paranoid network adjacent interpretation because a remote RDMA peer may not need local OS credentials on the target once it can access the RDMA fabric and the exposed queue or key material. The issue is not normally Internet reachable and is most relevant to local RDMA users or trusted internal RDMA, storage, or data center networks. Impact is at least denial of service via kernel crash and in worst case may allow limited confidentiality or integrity impact due to incorrect memory translation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5) YES DANGER NETWORK KPANIC MEMORY YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: ## 2. Signal breakdown Triggered signals: * Local unprivileged trigger: +1 If an rxe device and RDMA userspace access are available, a local user may be able to register MRs and exercise the affected translation path without full host root. * Remote reachable / network-triggerable in paranoid RDMA-adjacent interpretation: +2 A remote RDMA peer may influence RDMA READ or WRITE access once it has access to the RDMA fabric and valid queue or key material. This is not public Internet reachable in normal deployments, but it is network-adjacent in RDMA or storage fabrics. * Memory corruption, weak or indirect corruption candidate: +1 The bug is an incorrect IOVA-to-VA translation that can select the wrong page or wrong offset. This is a real memory access correctness issue, but the patch does not show arbitrary kernel write, controlled reclaim, type confusion, or function pointer corruption. * Reliable kernel crash / strong DoS: +1 The commit references a historical kernel panic related to this defect. * Confidentiality impact plausible: +1 RDMA READ using a wrong translated address may expose unintended memory within or near the registered mapping. * Integrity impact plausible: +1 RDMA WRITE using a wrong translated address may corrupt unintended memory within or near the registered mapping. Negative / limiting signals: * Rare AND difficult-to-reach subsystem/configuration: -1 RDMA/rxe is not usually enabled by default and practical exposure depends on configured SoftRoCE, RDMA userspace permissions, and MR page-size conditions. Not awarded: * Strong LPE plausibility: +0 No attacker-controlled reclaim, arbitrary write, refcount takeover, callback dispatch, or object confusion is shown. * Strong generic memory corruption: +0 The primitive is wrong memory translation, not a demonstrated kernel heap overwrite or arbitrary write. * Dirty-Pipe-like primitive: +0 No page-cache or COW ownership bypass is shown. ## 3. Reachability analysis The conservative trigger is local through RDMA/rxe userspace operations, assuming the rxe device exists and the user can access RDMA uverbs resources. Creating and configuring rxe itself may require administrative setup, but once exposed to users, MR registration and RDMA operations can be reachable by less privileged users depending on device node permissions and RDMA policy. The paranoid trigger is adjacent-network rather than Internet remote. A remote RDMA peer on the same RDMA or storage fabric may trigger the affected access path if it can issue RDMA operations against exposed queue pairs and valid memory keys. This is realistic for trusted internal RDMA, NVMe/RDMA, SRP, or data-center storage networks, but not for general Internet exposure. Namespaces and containers matter if RDMA devices are passed into containers or delegated to service accounts. In that case, the effective privilege can be closer to local low privilege rather than full host admin. ## 4. Severity interpretation This behaves above an ordinary Moderate because the bug affects memory translation in an RDMA data path and can plausibly cause wrong-memory reads, wrong-memory writes, and kernel panic. It is not a clear Important-class issue by itself because the patch does not demonstrate a strong kernel memory corruption primitive, privilege escalation chain, arbitrary write, or attacker-controlled object reuse. Theoretical impact includes limited confidentiality and integrity impact through incorrect RDMA address translation. Realistic demonstrated impact is stronger for DoS because a kernel panic was already associated with the defect. Therefore this should be treated as Actionable Moderate at minimum and should not be auto-closed without manual review. ## 5. One-sentence report phrase RDMA/rxe may translate an MR IOVA to the wrong virtual address when the MR page size differs from PAGE_SIZE, allowing local RDMA users or RDMA-adjacent peers with access to exposed queues and keys to cause unintended memory access and possible kernel panic. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: the bug is not just a validation cleanup or resource leak. It is an address-translation defect in an RDMA memory access path with plausible confidentiality, integrity, and availability impact, but the exact boundary of unintended memory access and privilege requirements depends on RDMA/rxe deployment, MR layout, device permissions, and whether remote peers can exercise the affected MRs. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE [ Upstream Commit: 409c2c5508f3d30627bea576f8676de523cb906e Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=409c2c5508f3d30627bea576f8676de523cb906e 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=409c2c5508f3d30627bea576f8676de523cb906e ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46325 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46325 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:L/I:L/A:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS score: 6.4 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: 5 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).