From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98740][MODERATE 7.0] EDAC/altera: Drop __init from ECC setup paths for re-probe safety Date: Sat, 24 Oct 2026 13:17:05 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98740 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: 4 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 List-Id: CVE: CVE-2026-98740 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: EDAC/altera: Drop __init from ECC setup paths for re-probe safety Commit: 9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98740 Analysis date: Sat, 24 Oct 2026 13:17:05 -0400 ActionableScore: 4 ActionableScore lower bound: unknown Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: Altera EDAC runtime reprobe can call freed `__init` setup code, causing a real stale-code execution condition with credible kernel-crash impact but no shown attacker-controlled reuse. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98740 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98740 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-2026-98740 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98740 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=4 LEGACY=MODERATE_KPANIC RESULT=SAME (final reconciliation agrees; DECISION: both MODERATE_KPANIC) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-416;*CWE-664;CWE-825;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'The Altera EDAC ECC setup callbacks were stored in runtime driver data but marked as init code. A deferred probe after EPROBE_DEFER or a later unbind and rebind can call an address in freed init memory, causing execution of stale or overwritten kernel text. The direct and credible impact is a kernel crash, while unintended control flow creates a plausible but unproven path to confidentiality or integrity impact. For the CVSS the PR:L value in the paranoid vector assumes a locally authenticated actor can influence reprobe through delegated device management or a service exposing rebind operations. Standard sysfs unbind normally requires administrative privilege. The issue is local, platform specific, and has high attack complexity because exploitation depends on device lifecycle conditions and the later contents of freed init memory. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 4 with recommendation Borderline / manual review recommended. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. No severity changing production threshold or specialist override was recorded. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. The independent weaker Aegis shadow evaluated CVSS 2.2 and ActionableScore 4 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4) MAYBE INIT UAF DMAorINTERRUPT HARDWARE LINUS KPANIC MEMORY - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 1. * Conservative score: 4. Real-UAF floor 4 applied: 1 -> 4. * Raw paranoid score: 1. * Paranoid score: 4. The same floor applies; no evidence-supported extra leverage point. * Final recommended bucket: **Borderline / manual review recommended**:: 2. Signal breakdown * +2 — Real post-lifetime use: runtime probe invokes setup callbacks whose executable `__init` memory may already have been freed. * +1 — Plausible kernel crash/strong DoS from branching into freed or overwritten init text. * -2 — Rare hardware-only exposure: affected code is specific to Altera SoC EDAC peripherals and requires that platform. * Floor 4 — This is execution through a stale function target, not merely a shallow read from fixed stale storage. * No controlled replacement, attacker-controlled reclaimed contents, arbitrary write, disclosure, or demonstrated LPE. * No separate confidentiality or integrity point: unintended control flow is plausible, but useful attacker influence over the freed init memory is not shown. * No timing penalty: deferred probing is an ordered lifecycle condition, not proven to require a narrow race. * B5-R is inapplicable: no retry-accumulated heap OOB write exists. * B4-PENDING is inapplicable: no authorization decision or missing security guard exists. 3. Reachability analysis A deferred probe can invoke the stale callback after init memory is released, but the evidence does not show an attacker controlling dependency timing. Manual sysfs unbind/rebind is another path and normally requires administrative device-management authority. No below-host-admin, delegated, or namespace-scoped complete trigger is established. The required Altera hardware and enabled peripheral-specific EDAC path materially restrict exposure. 4. Primitive and severity reading The primitive is an indirect call into freed init-text storage: a real lifetime violation involving executable code, classified as CLASS_B. The shown consequence is a kernel fault or unintended instruction execution. Useful control-flow influence, controlled reuse, or a protected-state effect remains unproven. Because the available paths are hardware-specific and attacker reachability is unresolved, this is not presently an Important candidate and may be downgraded after review. 5. One-sentence report phrase Altera EDAC runtime reprobe can call freed `__init` setup code, causing a real stale-code execution condition with credible kernel-crash impact but no shown attacker-controlled reuse. 6. Manual review advice MANUAL CHECK RECOMMENDED Confirm whether any product service or delegated device-management interface permits a below-host-admin actor to induce deferred reprobe or rebind. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: EDAC/altera: Drop __init from ECC setup paths for re-probe safety Commit: 9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 Commit description: Sashiko reports: "Does suppressing sysfs unbinding fully prevent the execution of freed __init memory? If altr_sysmgr_regmap_lookup_by_phandle() returns -EPROBE_DEFER, the probe is deferred until after __init memory is freed." The a10 EDAC .setup callbacks (sdmmc, ethernet, nand, dma, usb, qspi) and their helpers (altr_init_a10_ecc_device_type, altr_init_a10_ecc_block) were marked __init. These run from the probe path, which may execute after init memory is freed -- e.g. a probe deferred via -EPROBE_DEFER that only succeeds once a late/module dependency appears, or a manual unbind/rebind. Calling __init code then dereferences freed memory. Remove __init so these functions remain valid at runtime. Fixes: 788586e ("EDAC/altera: Initialize peripheral FIFOs in probe()") Assisted-by: LLM Signed-off-by: Dinh Nguyen Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org # 6.18+ Link: https://patch.msgid.link/20260911120627.2634225-3-dinguyen@kernel.org Signed-off-by: Greg Kroah-Hartman Changed files: drivers/edac/altera_edac.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=9846b85c2eb8b749c3f14bdcc31b1070f6aabba8 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98740 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98740 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:H/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7 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: 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).