From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-68396][MODERATE REGULAR] scsi: core: wake eh reliably when using scsi_schedule_eh [ Upstream Date: Mon, 10 Aug 2026 15:02:08 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-68396 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: 4 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 866efe8ae8b8b4d095501001b026e1022734be28 List-Id: CVE: CVE-2026-68396 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: scsi: core: wake eh reliably when using scsi_schedule_eh [ Upstream Commit: 866efe8ae8b8b4d095501001b026e1022734be28 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=866efe8ae8b8b4d095501001b026e1022734be28 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68396 Analysis date: Mon, 10 Aug 2026 15:02:08 -0400 ActionableScore: 4 ActionableScore lower bound: unknown Actionable bucket: Borderline manual review recommended / not Important Manual review required: YES Summary: A race in SCSI error recovery can prevent the error handler from waking after commands time out or become inactive, causing persistent stuck I/O and denial of service for the affected storage host. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68396 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68396 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-2026-68396 MODERATE CHECK WITH IMPACT FROM ORIG NN LOW 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:N/A:H';CWE-362;CWE-662;CWE-667;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.3';DESCR 'A race in SCSI error recovery can leave the error handler thread asleep because scsi_schedule_eh and scsi_dec_host_busy may observe host recovery state and command activity in different orders. This can prevent error recovery from running after commands time out or become inactive, causing stuck I/O and denial of service for the affected SCSI host. For the CVSS the PR:N paranoid case assumes the attacker can act as a failing or malicious storage endpoint on a reachable SCSI transport and does not need a local account on the host. The issue is not a general Internet reachable bug and normally depends on a storage fabric, a device fault path, or local I/O activity that can drive SCSI timeout and recovery behavior. Impact is availability loss only, with no supported confidentiality or integrity impact because the patch indicates ordering and wakeup failure rather than memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline manual review recommended / not Important (with actual score 4) YES LOCK DANGER INIT RACE ERRORPATH HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 4 * Final recommended bucket: **Borderline manual review recommended / not Important**:: ## 2. Signal breakdown Triggered signals: * Local unprivileged trigger: +1 A local user can generate SCSI I/O, but reliable triggering depends on timeout or error-recovery conditions. * Reliable kernel crash / strong DoS: +1 The error handler thread may never wake, leaving SCSI recovery stuck and I/O hung. * Availability impact realistic: +1 The impact can persist as a stuck storage host or blocked I/O path, not merely a transient warning. * Important filesystem/storage path: +1 This is SCSI core error handling, affecting storage recovery. * Broad/default/common subsystem: +1 SCSI core is broadly used across real storage deployments. Subtracted signals: * Hard or unreliable race / special timing required: -1 The issue depends on a race between error-state visibility and busy-command accounting. Not applied: * No generic memory corruption. The patch fixes ordering and wakeup reliability, not UAF, OOB, double-free, or stale object reuse. * No privilege escalation plausible. There is no demonstrated corruption primitive or security-boundary bypass. * No confidentiality or integrity impact. The observed effect is availability loss only. ## 3. Reachability analysis The conservative trigger is local I/O activity combined with SCSI timeout or error recovery. A normal unprivileged user may be able to generate I/O, but usually cannot reliably force the exact device error or timing condition. The paranoid interpretation considers externally influenced storage paths, such as a failing or malicious storage endpoint on a reachable storage fabric. This is not general Internet remote reachability, so I do not award full remote network-triggerable scoring. Namespaces and containers do not clearly lower privileges for direct control of the SCSI recovery path. However, container workloads can generate I/O against host-backed storage, so operational exposure may exist in multi-tenant environments. ## 4. Severity interpretation This behaves like an actionable storage DoS race, not an Important-class memory corruption issue. The patch uses `synchronize_rcu()` and delayed work to enforce visibility ordering before `scsi_host_busy()` and `scsi_eh_wakeup()`, which supports a race or ordering classification. Theoretical impact is limited to a stuck error recovery path and unavailable storage. Realistic exploitation requires either local I/O plus fault timing, or influence over an attached storage endpoint. There is no evidence of UAF, overwrite, object replacement, callback corruption, or privilege escalation. ## 5. One-sentence report phrase A race in SCSI error recovery can prevent the error handler from waking after commands time out or become inactive, causing persistent stuck I/O and denial of service for the affected storage host. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: this is a race in core storage recovery code with possible externally influenced storage-fabric conditions, but no demonstrated memory corruption or privilege escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: scsi: core: wake eh reliably when using scsi_schedule_eh [ Upstream Commit: 866efe8ae8b8b4d095501001b026e1022734be28 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=866efe8ae8b8b4d095501001b026e1022734be28 Changed files: drivers/scsi/hosts.c drivers/scsi/scsi_error.c drivers/scsi/scsi_priv.h include/scsi/scsi_host.h 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=866efe8ae8b8b4d095501001b026e1022734be28 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68396 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68396 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:N/I:N/A:H The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.3 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: 4 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).