From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-99214][LOW] drm/vc4: hdmi: Move packet RAM enable to PM runtime [ Upstream Date: Thu, 29 Oct 2026 00:23:42 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-99214 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 2 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 List-Id: CVE: CVE-2026-99214 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: drm/vc4: hdmi: Move packet RAM enable to PM runtime [ Upstream Commit: 6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99214 Analysis date: Thu, 29 Oct 2026 00:23:42 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: A local HDMI audio preparation sequence can reach disabled Packet RAM, causing a kernel warning and limited HDMI availability degradation without evidence of memory corruption or privilege bypass. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-99214 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99214 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: LOW 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-2026-99214 LOW https://www.kernelcve.org/list/?q=CVE-2026-99214 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT LOW AEGIS_AS=1 LEGACY=LOW RESULT=SAME (final reconciliation agrees; DECISION: both LOW) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';CWE-362;*CWE-664;CWE-754;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '3.3';DESCR 'Audio preparation can run after an HPD event but before the HDMI video path has been restored. In that state vc4_hdmi_write_infoframe can attempt to store an audio infoframe while Packet RAM is disabled and trigger a kernel warning. For the CVSS the PR:L value reflects that reliable triggering normally requires a local user or process able to start HDMI audio and exercise the affected display power sequence. The demonstrated impact is limited HDMI audio or display availability degradation. There is no supported UAF, OOB access, information leak, arbitrary write, or privilege escalation primitive. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 3.3 and the production ActionableScore returned 2 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. No severity changing production threshold or specialist override was recorded. 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. The independent weaker Aegis shadow evaluated CVSS 3.3 and ActionableScore 1 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was LOW. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) MAYBE LOCK WARNONLY LEAK HARDWARE LINUS PACKET - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES RequiresHostUID0=NO AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 2 * Conservative score: 2; no floor or cap applied. * Raw paranoid score: 2 * Paranoid score: 2; no additional technically supported impact. * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Local below-host-admin trigger: the trace shows `wireplumber` reaching the affected HDMI audio preparation path through an ALSA ioctl. * +1 Device availability impact: writing an audio infoframe while Packet RAM is disabled can disrupt HDMI audio/display operation. * +0 WARN-only symptom: the demonstrated result is a kernel warning, not a supported panic or host-wide fatal fault. * No UAF, OOB access, memory write outside the intended hardware register operation, stale object, authorization bypass, information disclosure, or privilege-escalation primitive is shown. * No B5-R retry-accumulated overwrite or B3 shared-backing write exists. * No extra availability point: only the same device-local degradation is evidenced. 3. Reachability analysis A local userspace audio client or service with access to the HDMI PCM device can invoke preparation during the HPD/video-restoration ordering window. The supplied trace grounds below-host-admin execution, but does not establish namespace-scoped capabilities. Raspberry Pi VC4 HDMI hardware is required, but this is ordinary target hardware rather than a rare physical attack prerequisite. The defect is an ordering/state-sequencing issue; no materially difficult race is demonstrated. 4. Primitive and severity reading The primitive is invalid hardware power-management state: Packet RAM may be disabled when the audio infoframe path needs it. The fix keeps Packet RAM enabled throughout runtime-active operation and disables it only during runtime suspend. This is CLASS_C device-state/availability behavior, with no active structured-state corruption or useful effect past the warning and HDMI degradation. ImportantCandidate is therefore NO, and automatic downgrade is allowed. 5. One-sentence report phrase A local HDMI audio preparation sequence can reach disabled Packet RAM, causing a kernel warning and limited HDMI availability degradation without evidence of memory corruption or privilege bypass. 6. Manual review advice NO MANUAL CHECK NEEDED The patch and call trace support only a device-local sequencing defect with no unresolved security primitive. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/vc4: hdmi: Move packet RAM enable to PM runtime [ Upstream Commit: 6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 Changed files: drivers/gpu/drm/vc4/vc4_hdmi.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=6b03e354526f6bad60ed3a7f08fec8b7d29d2f27 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-99214 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99214 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:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS score: 3.3 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: 2 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: LOW KPANIC detected for this report: NO Published priority for this report (same as in Subject): LOW 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).