From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98932][MODERATE 7.0] EDAC/altera: Fix use-after-free in error paths Date: Tue, 27 Oct 2026 00:15:35 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98932 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: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 865f3bdebbc9b34012358c377c9b15154f95f33b List-Id: CVE: CVE-2026-98932 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: EDAC/altera: Fix use-after-free in error paths Commit: 865f3bdebbc9b34012358c377c9b15154f95f33b Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=865f3bdebbc9b34012358c377c9b15154f95f33b Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98932 Analysis date: Tue, 27 Oct 2026 00:15:35 -0400 ActionableScore: 0 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: An Altera EDAC setup-error race can leave an IRQ handler dereferencing freed control state before managed IRQ unregistration, plausibly crashing affected systems. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98932 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98932 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-98932 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98932 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=5 LEGACY=MODERATE_KPANIC RESULT=SAME V39_AEGIS_ONE_STEP_UP=MODERATE->MODERATE_KPANIC (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:H/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-362;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '6.4';DESCR 'An error path race in the Altera EDAC setup code frees dci before devres unregisters the managed IRQ handlers. An interrupt in this window can execute a handler with data derived from freed dci pvt_info, creating a concrete UAF dereference and possible writes through EDAC handling. A kernel crash is the clearest impact, while memory corruption may occur if the freed allocation is reused before the handler completes. For the CVSS the PR:H value is used because reliable triggering normally requires control over platform device setup or failure injection together with an ECC interrupt, which is not shown to be available to an ordinary local user. The issue is hardware and timing dependent and is not network reachable. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 6.4 and the production ActionableScore returned 0 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were ActionableScore thresholds stage MODERATE_KPANIC to MODERATE because the ActionableScore threshold rule was applied. final reconciliation stage MODERATE to MODERATE_KPANIC because the cross model evidence reconciliation rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 2.7 and ActionableScore 5 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0) MAYBE INIT ERRORPATH UAF HARDWARE LINUS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 KPANIC V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 0. * Conservative score: 0; no floor or cap applied. * Raw paranoid score: 0. * Paranoid score: 0; no additional exploit primitive is supported. * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +2 — Real UAF: `dci` is freed while managed IRQ handlers remain registered and may dereference data derived from `dci->pvt_info`. * +1 — Plausible kernel crash: an IRQ in the vulnerable interval can dereference freed storage. * -1 — Hard timing: setup must enter an error path and an IRQ must fire in the narrow interval before devres unregisters the handlers. * -2 — Rare hardware dependency: the path is specific to Altera Arria10 EDAC-capable platform hardware. * No UAF floor: this is specialized asynchronous stale storage with a narrow teardown/error interval; material replacement or deeper structured consumption is not shown. * Controlled reclaim, attacker-shaped replacement contents, arbitrary write, repeated release, disclosure, and LPE are not shown. * The hints’ “possible writes through EDAC handling” is not substantiated by the supplied handler code, so no structured-leverage or integrity point is awarded. * No extra availability point: it would duplicate the same possible crash. 3. Reachability analysis The vulnerable ordering is confirmed, but attacker reachability is not. Triggering requires device setup failure plus an ECC-related IRQ on supported hardware. The evidence does not show that an ordinary user, delegated service, or namespace-scoped capability can initiate the complete sequence. It also does not positively establish that host-administrator powers are mandatory, so `HostAdminRequired` remains unknown. The platform-device/EDAC path is not namespace scoped. The race appears narrow and hardware-dependent rather than cheaply repeatable by a demonstrated attacker. 4. Primitive and severity reading This is a genuine Class B asynchronous UAF involving an EDAC control object. The stale IRQ handler dereference is broader than a purely theoretical lifetime bug, but the supplied evidence supports principally a fault/crash outcome. It does not identify a post-reclaim field consumer, controlled write, callback redirection, or security-boundary crossing. Therefore it is not an Important candidate, and downgrade remains allowed after review. 5. One-sentence report phrase An Altera EDAC setup-error race can leave an IRQ handler dereferencing freed control state before managed IRQ unregistration, plausibly crashing affected systems. 6. Manual review advice MANUAL CHECK RECOMMENDED Confirm IRQ-handler operations and whether any realistic non-admin actor can induce both setup failure and the interrupt window. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: EDAC/altera: Fix use-after-free in error paths Commit: 865f3bdebbc9b34012358c377c9b15154f95f33b Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=865f3bdebbc9b34012358c377c9b15154f95f33b Commit description: In both altr_edac_a10_device_add() and altr_portb_setup(), the error path freed the dci structure before releasing the devres group. Since the managed single and double bit IRQ handlers use altdev(dci->pvt_info) as their data, an IRQ firing between freeing dci and unregistering the IRQs could dereference the freed memory. Release the devres group first so the managed IRQs are unregistered before the dci structure is freed. Fixes: 9110498 ("EDAC, altera: Add Arria10 SD-MMC EDAC support") Fixes: 588cb03 ("EDAC, altera: Add Arria10 L2 Cache ECC handling") Closes: https://sashiko.dev/#/patchset/20260719211238.589402-1-rosenp%40gmail.com 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/20260911120627.2634225-5-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=865f3bdebbc9b34012358c377c9b15154f95f33b ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98932 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98932 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:H/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 6.4 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: 0 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).