From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-90412][MODERATE REGULAR] nvmet: fix return status of RMI log page on allocation failure [ Upstream Date: Fri, 18 Sep 2026 05:00:04 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-90412 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 2 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 9e136150ac55df4b7ea36e6110ffa39d08905f37 List-Id: CVE: CVE-2026-90412 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: nvmet: fix return status of RMI log page on allocation failure [ Upstream Commit: 9e136150ac55df4b7ea36e6110ffa39d08905f37 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9e136150ac55df4b7ea36e6110ffa39d08905f37 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90412 Analysis date: Fri, 18 Sep 2026 05:00:04 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: The NVMe target RMI log page handler can incorrectly report command success after a log buffer allocation failure, causing a connected host to receive a misleading success status without a demonstrated crash, disclosure, corruption, or privilege escalation impact. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90412 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90412 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 REGULAR 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-2026-90412 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-90412 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L';CWE-703;CWE-252;CWE-755;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N';BEST CVSS score: '4.2';DESCR 'An error handling bug in the NVMe target RMI log page path can report NVME_SC_SUCCESS when kzalloc for the log buffer fails. The host can be told that the Get Log Page command succeeded even though the target did not prepare or transfer the requested data. For the CVSS the PR:N is used because a connected NVMe target host does not need additional privileges beyond access to the target endpoint. The issue is reachable through an NVMe target fabric or storage network, but exploitation depends on an allocation failure and is therefore high complexity. Impact is mainly low integrity impact due to a misleading protocol success status. No UAF, OOB access, kernel crash, or privilege escalation is indicated by the code path.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES SIMPLEFIX NVME LOG LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 PrimitiveClass=NONE RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES ## 1. ActionableScore * Raw conservative score: 2 * Conservative score: 2. No floor or cap applied. * Raw paranoid score: 2 * Paranoid score: 2. No floor or cap applied. * Final recommended bucket: **Ordinary Moderate**:: ## 2. Signal breakdown Positive signals: * +2 Remote or fabric reachable protocol path: a connected NVMe target host can issue the affected Get Log Page RMI command over an NVMe fabric or storage network path. Negative or non-awarded signals: * +0 Real UAF not awarded: no stale pointer, post-free use, double release, refcount misuse, or lifetime violation is shown. * +0 Kernel crash or strong DoS not awarded: the patch describes false success status on allocation failure, not panic, NULL dereference, lockup, or host-wide failure. * +0 Confidentiality not awarded: no information disclosure or read-back of unintended kernel data is established. * +0 Integrity not awarded as kernel integrity impact: the incorrect success status is a protocol correctness problem, but no unauthorized modification of protected kernel state or storage data is shown. * +0 Strong exploitation leverage not awarded: no controlled reclaim, arbitrary write, OOB access, type confusion, or privilege escalation primitive is present. * +0 Resource exhaustion not awarded: kzalloc failure is a prerequisite state, not caused by this bug. * No privilege penalty applied: host-admin-equivalent privilege on the target is not required for a host already allowed to access the NVMe target endpoint. ## 3. Reachability analysis The vulnerable path is in `nvmet_execute_get_log_page_rmi()` in the NVMe target admin command handling path. A connected NVMe host can request the RMI log page, but the incorrect behavior only occurs if allocation of the log buffer fails. The attacker model is a host or initiator that can reach the NVMe target endpoint. This does not require host administrator privilege on the target, so `HostAdminRequired=NO`. It does require prior existence and exposure of the NVMe target service, but that is normal deployment state rather than a privilege needed to trigger the specific command. This is not a namespace-scoped local capability issue, so `NamespaceScopedPrivilege=NO`. No special race is involved. The practical complexity is elevated by needing memory allocation failure at the relevant point. ## 4. Primitive and severity interpretation The exact primitive is incorrect error/status propagation. `status` may remain `NVME_SC_SUCCESS` after `nvmet_req_find_ns()` succeeds, and if `kzalloc_obj(*log)` fails, the function jumps to `out` and completes the request as successful even though no RMI log data was prepared. This is not an active structured UAF, fixed stale storage, repeated release/refcount mutation, OOB access, or memory corruption primitive. The demonstrated consequence is a misleading protocol success result. The speculative consequence is possible host-side confusion or degraded error handling under memory pressure, but the patch does not support privilege escalation, kernel data disclosure, storage corruption, or kernel crash. Primitive class is `NONE`. `ImportantCandidate=NO` because no Important-preserving primitive is established. `AutoDowngradeAllowed=YES` because the issue is a low-impact protocol error-handling bug without unresolved memory corruption or security-boundary leverage. ## 5. One-sentence report phrase The NVMe target RMI log page handler can incorrectly report command success after a log buffer allocation failure, causing a connected host to receive a misleading success status without a demonstrated crash, disclosure, corruption, or privilege escalation impact. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: the issue is reachable from a connected NVMe target host, but the established primitive is only incorrect error reporting on allocation failure and appears suitable for low-priority handling if no product-specific higher impact is found. ## 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: nvmet: fix return status of RMI log page on allocation failure [ Upstream Commit: 9e136150ac55df4b7ea36e6110ffa39d08905f37 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9e136150ac55df4b7ea36e6110ffa39d08905f37 Changed files: drivers/nvme/target/admin-cmd.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=9e136150ac55df4b7ea36e6110ffa39d08905f37 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90412 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90412 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:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L The Best / paranoid CVSS score: 4.2 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: unknown 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: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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).