From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-90230][MODERATE 7.0] nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate() [ Upstream Date: Fri, 18 Sep 2026 02:46:28 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-90230 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: 89ff11b72f38976f3b5aea23a5228ee05e277209 List-Id: CVE: CVE-2026-90230 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate() [ Upstream Commit: 89ff11b72f38976f3b5aea23a5228ee05e277209 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=89ff11b72f38976f3b5aea23a5228ee05e277209 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90230 Analysis date: Fri, 18 Sep 2026 02:46:28 -0400 ActionableScore: 5 ActionableScore lower bound: 4 Actionable bucket: Actionable Moderate Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90230 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90230 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-2026-90230 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-90230 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H';CWE-125;*CWE-20;CWE-130;Other CVSS 'AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H';BEST CVSS score: '8.1';DESCR 'A heap out-of-bounds read in the NVMe target authentication path occurs because nvmet_auth_negotiate can read DH-HMAC-CHAP negotiate fields and idlist entries without validating the host supplied transfer length or the halen and dhlen counters. A malicious or non conformant NVMe host can provide a too small tl or oversized identifier counts, causing reads beyond the allocated authentication buffer during negotiate processing. For the CVSS the PR:N is used because the attacker only needs protocol reachability to the NVMe target authentication endpoint and does not need a local account on the target system. The AV:A metric is used because NVMe over Fabrics targets are normally deployed on isolated storage or data center networks rather than the public Internet. Impact is at least denial of service via kernel crash or fault handling, with possible confidentiality impact from reading adjacent heap data through protocol dependent behavior. Integrity impact is not assumed because the patch shows an out-of-bounds read and length validation issue, not an out-of-bounds write or arbitrary write primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate (with actual score 5) YES OOB SIMPLEFIX NVME LINUS KPANIC DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=4 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=REQUIRED AutoDowngradeAllowed=NO 1. ActionableScore * Raw conservative score: 4 * Conservative score: 4 * Raw paranoid score: 5 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate**:: No floor or cap was applied. The paranoid score is used as ActionableScore because the bug is protocol-reachable and the heap OOB read may have more than purely local crash relevance, but the evidence still does not establish a write primitive, UAF, controlled reclaim, or LPE. 2. Signal breakdown Positive conservative signals: * +2: Network or network-adjacent protocol reachability. A malicious or non-conformant NVMe host can send malformed DH-HMAC-CHAP negotiate data to an exposed NVMe target authentication endpoint. * +1: Read-only heap OOB primitive. nvmet_auth_negotiate can index beyond the allocated authentication message buffer because tl, halen, and dhlen were not validated. * +1: Plausible availability impact. Invalid kernel heap reads in this parser can plausibly cause fault handling, KASAN reports, or a target-side crash depending on layout and build. Positive paranoid signals: * +1: Plausible limited confidentiality concern. The OOB bytes can influence protocol negotiation behavior, such as selected or rejected hash and DH identifiers, so a limited protocol-dependent oracle cannot be ruled out from the patch alone. Non-awarded signals: * Controlled reclaim not demonstrated. * Arbitrary write not demonstrated. * UAF not demonstrated. * Integrity impact not awarded because the patch shows read-only OOB access, not an OOB write or state overwrite. * Strong LPE or Important-grade exploitation leverage not awarded. * Extra availability point not awarded because no distinct persistent outage beyond possible crash is shown. * Class A not used because no strong corruption, authorization bypass, or demonstrated privilege escalation is established. * Class B not used because this is not a lifetime, ownership, RCU, repeated-release, or active-object stale reference bug. Negative signals: * No host-admin penalty applied. The attacker does not need host admin on the target once the NVMe target endpoint is exposed. * No race penalty applied. The trigger is malformed protocol input, not a timing race. * No rare-hardware penalty applied. NVMe-oF target deployment is specialized, but the vulnerable path is a normal protocol feature when in-band authentication is enabled. 3. Reachability analysis The evaluated attacker is a malicious or non-conformant NVMe host that can reach the NVMe target authentication endpoint. The attacker does not need a local account or host administrator privileges on the target system. The vulnerable operation is reached through the NVMe target authentication protocol path during DH-HMAC-CHAP negotiation. A prior privileged setup is required in the operational sense because an administrator must have configured an NVMe target and enabled the relevant authentication path. That is a deployment prerequisite, not an attacker privilege requirement. This does not justify HostAdminRequired=YES. The issue is best treated as network-adjacent rather than broad Internet exposure. NVMe/TCP and NVMe-oF targets are typically deployed on isolated storage or data-center networks. Practical exploitation usually requires access to that storage network or to a host allowed to initiate NVMe target connections. No namespace-scoped privilege chain is relevant from the supplied patch. No race or special timing is required. No special rare hardware dependency is established beyond use of the NVMe target subsystem and the authentication feature. 4. Primitive and severity interpretation The exact primitive is a heap out-of-bounds read in nvmet_auth_negotiate. The function parses a host-supplied DH-HMAC-CHAP negotiate buffer and reads fields and idlist entries without first validating that the supplied transfer length covers the accessed structure and without bounding halen and dhlen to the protocol maximums. This is not a UAF and not a repeated lifetime or refcount mutation. The stale-object and repeated-release rules do not apply. The affected storage is an authentication message buffer, not an active structured kernel object with demonstrated post-free reuse or attacker-shaped replacement. The demonstrated consequence is invalid kernel heap read during protocol parsing. The plausible practical impacts are denial of service and possibly limited confidentiality exposure through protocol-dependent behavior. The speculative consequence would be broader kernel memory disclosure, but the patch does not establish a direct byte-for-byte readback channel or arbitrary read primitive. PrimitiveClass=CLASS_C because the established primitive is read-only OOB access without a demonstrated independently useful corruption primitive. ImportantCandidate=NO because there is no Class A primitive and no strong Class B lifetime or ownership primitive. AutoDowngradeAllowed=NO because this is still a protocol-reachable kernel heap OOB read in an authentication path with unresolved disclosure and crash behavior, so automatic closure as ordinary low-risk Moderate would be unsafe. Likely operational severity is Actionable Moderate. It should be manually reviewed, especially for product configurations exposing NVMe/TCP or NVMe-oF authentication to untrusted or semi-trusted hosts. 5. One-sentence report phrase A heap out-of-bounds read in NVMe target DH-HMAC-CHAP negotiation allows a reachable NVMe host to send malformed authentication data that can make the kernel read past the allocated message buffer, causing possible DoS and limited protocol-dependent disclosure risk. 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: protocol-reachable kernel heap OOB read in an authentication path, with possible DoS and unresolved limited disclosure behavior. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate() [ Upstream Commit: 89ff11b72f38976f3b5aea23a5228ee05e277209 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=89ff11b72f38976f3b5aea23a5228ee05e277209 Changed files: drivers/nvme/target/fabrics-cmd-auth.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=89ff11b72f38976f3b5aea23a5228ee05e277209 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90230 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90230 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:L/PR:N/UI:N/S:U/C:L/I:N/A:H The Best / paranoid CVSS vector: AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H The Best / paranoid CVSS score: 8.1 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).