From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-90293][MODERATE REGULAR] IB/isert: post the full-feature receive buffers after session registration [ Upstream Date: Thu, 17 Sep 2026 18:59:44 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-90293 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: 3 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 962edb9a6b0dae09d33a677485a398fc7d55968c List-Id: CVE: CVE-2026-90293 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: IB/isert: post the full-feature receive buffers after session registration [ Upstream Commit: 962edb9a6b0dae09d33a677485a398fc7d55968c Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=962edb9a6b0dae09d33a677485a398fc7d55968c Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90293 Analysis date: Thu, 17 Sep 2026 18:59:44 -0400 ActionableScore: 3 ActionableScore lower bound: unknown Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90293 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90293 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: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-90293 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-90293 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H';CWE-362;**CWE-476;CWE-754;Other CVSS 'AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7.5';DESCR 'An iSER target session ordering bug allows full feature receive buffers to be posted before __transport_register_session() has completed. A malicious or non compliant initiator can send a SCSI command before waiting for the final Login Response, so the command may reach target_submit() while se_session.se_tpg is still NULL, causing a kernel oops and denial of service. For the CVSS the PR:N is used because a remote initiator generally needs only network access to the iSER target and no local account on the victim, although real deployments may restrict initiators by storage fabric policy or authentication. The issue is network reachable over RDMA based iSER, mostly in InfiniBand, RoCE, or iWARP storage networks rather than the public Internet. Impact is denial of service via kernel crash. No concrete information disclosure, arbitrary write, or privilege escalation primitive is shown by this patch context.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3) YES LOCK NETWORK LOG TIMER LINUS TEST INCREASED_TO_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 3 * Conservative score: 3. No floor or cap applied. * Raw paranoid score: 3 * Paranoid score: 3. No floor or cap applied. * Final recommended bucket: **Borderline / manual review recommended**:: 2. Signal breakdown Positive signals: * +2 Remote reachable / directly network-triggerable: a remote iSER initiator can send an early SCSI command before waiting for the final Login Response and reach the vulnerable target path. * +1 Reliable kernel crash / strong DoS: the commit directly reports kernel oops at target_submit when se_session.se_tpg is NULL. Negative signals: * 0 No host-admin penalty: attacker does not need local host-admin privileges on the target, only reachability as an iSER initiator. * 0 No race/timing penalty: this is mainly an ordering/protocol-state bug. The early send can be deliberately attempted, and reported testing showed frequent oopses on unpatched builds. * 0 No rare-hardware penalty: iSER/RDMA is specialized, but the evidence includes rxe testing and common RDMA storage deployments. Specialized subsystem alone is not enough for a penalty. Important non-awarded signals: * RealUAF not awarded: the established primitive is NULL se_tpg dereference, not use-after-free. * Controlled reclaim not demonstrated. * Arbitrary write not demonstrated. * Confidentiality and integrity not awarded. * Extra availability not awarded because the same kernel oops is already counted as reliable DoS. * Concrete repeated release/refcount not present. * Structured stale-object leverage not awarded because no stale post-lifetime object reuse is established. * Strong LPE or privilege escalation not awarded. 3. Reachability analysis The attacker is a remote iSER initiator with network or fabric access to the iSER target. No local account on the victim host is required, so HostAdminRequired=NO. The trigger is not namespace-scoped and does not depend on attacker-created Linux namespaces. NamespaceScopedPrivilege=NO. Prior target configuration is required in the normal sense that the victim must be running an iSER target, but that is the exposed service being attacked, not an attacker prerequisite requiring host-admin access. The attack is relevant mainly to RDMA storage fabrics such as InfiniBand, RoCE, or iWARP. It is typically not public Internet exposure, but it is still externally reachable within storage or data-center networks. The bug is not a hard race in the scoring sense. It depends on the initiator violating expected ordering by sending before the final Login Response, but this behavior is attacker-controllable. 4. Primitive and severity interpretation The exact primitive is invalid state leading to NULL pointer dereference: an early SCSI command can be processed against an se_session where se_tpg is still NULL. This is not active structured UAF and not fixed stale storage. It is a protocol/session registration ordering flaw causing a crash. PrimitiveClass=CLASS_C because demonstrated behavior is crash/DoS through NULL dereference without an independently useful corruption primitive. Demonstrated consequence: kernel oops / denial of service. Speculative consequence: stronger exploitation is not supported by the supplied patch context. ImportantCandidate=NO because there is no UAF, no repeated lifetime mutation, no controlled overwrite, no authorization bypass, and no demonstrated C/I impact. AutoDowngradeAllowed=YES because the issue is a network-reachable crash-only Class C bug without unresolved memory-corruption or security-boundary leverage. Manual review is still recommended due to remote/fabric reachability and kernel crash. Likely operational severity: high CVSS-style availability impact in exposed iSER target deployments, but ActionableScore remains borderline because the primitive is DoS-only. 5. One-sentence report phrase A remote or fabric-reachable iSER initiator can send a SCSI command before the final Login Response and cause target_submit to dereference a NULL se_tpg, leading to a kernel crash and denial of service. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: network/fabric reachability and a reliable kernel oops justify review, but no UAF, memory corruption, privilege escalation, authorization bypass, or C/I primitive is established. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: IB/isert: post the full-feature receive buffers after session registration [ Upstream Commit: 962edb9a6b0dae09d33a677485a398fc7d55968c Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=962edb9a6b0dae09d33a677485a398fc7d55968c Changed files: drivers/infiniband/ulp/isert/ib_isert.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=962edb9a6b0dae09d33a677485a398fc7d55968c ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90293 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90293 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:N/I:N/A:H The Best / paranoid CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 7.5 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: unknown Paranoid ActionableScore: 3 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).