From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-74295][LOW] ASoC: codecs: hdac_hdmi: Validate written enum value [ Upstream Date: Sat, 15 Aug 2026 04:47:45 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-74295 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: 216336418c007c4b44c650acf2fd3d2de5bb81e8 List-Id: CVE: CVE-2026-74295 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ASoC: codecs: hdac_hdmi: Validate written enum value [ Upstream Commit: 216336418c007c4b44c650acf2fd3d2de5bb81e8 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=216336418c007c4b44c650acf2fd3d2de5bb81e8 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74295 Analysis date: Sat, 15 Aug 2026 04:47:45 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A local ALSA control write can provide an out-of-range HDMI codec enum value that is used to index `e->texts` before validation, causing a limited out-of-bounds read and possible local DoS without evidence of privilege escalation. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74295 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74295 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-2026-74295 LOW CHECK WITH IMPACT FROM ORIG NN 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:L/I:N/A:L';CWE-125;CWE-129;*CWE-20;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'An out of range ALSA enum value can be used as an index into e->texts in hdac_hdmi_set_pin_port_mux before snd_soc_dapm_put_enum_double validates the value. This creates a local out of bounds read in the hdac_hdmi codec control path when a caller writes an invalid pin port mux enum item. For the CVSS the PR:L is used because practical triggering requires a local user or process with access to the affected ALSA control rather than remote network access. The issue is not network reachable and is not triggered by audio packets or HDMI traffic. Impact is mainly local denial of service through a possible warning or crash. A small confidentiality impact is kept only in the paranoid score because the primitive is an invalid read, but the rejected value path does not show a clear data disclosure channel or write primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) YES OOB SIMPLEFIX HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Triggered signals: * Local unprivileged trigger: +1 A local process with access to the affected ALSA control can write an invalid enum value. * Availability impact realistic: +1 The bug is an out-of-bounds read of `e->texts[index]` before validation. A bad index may cause a warning, KASAN report, or possible kernel fault depending on memory layout. Not triggered: * Remote reachable: +0 This is not reachable over the network. * Generic memory corruption: +0 The primitive is a read-only array over-index before validation, not UAF, OOB write, double-free, type confusion, or arbitrary write. * Privilege escalation plausible: +0 No reclaim, overwrite, stale callback, refcount abuse, or attacker-controlled object replacement is shown. * Confidentiality impact: +0 The out-of-bounds value is read into a local pointer and the invalid write is then rejected. There is no clear user-visible disclosure channel. * Integrity impact: +0 No write primitive or state corruption is shown. ## 3. Reachability analysis The bug is reachable through a local ALSA/ASoC control write path for the HDMI codec. Triggering requires local code execution and access to the relevant sound control, so PR:L is the practical model. Containers and namespaces do not generally make this remotely reachable, but device pass-through or delegated audio access could expose it to less trusted local users. The affected path is device and codec dependent, not a broad default kernel interface for all systems. Call-site confidence: high. The relevant function and validation order are visible in the patch. ## 4. Severity interpretation This behaves like a low-end local Moderate or Low-like issue. The theoretical primitive is an invalid kernel read before bounds validation, but the patch does not support memory corruption, privilege escalation, or information disclosure. Realistic impact is mostly local DoS or diagnostic warning behavior. ## 5. One-sentence report phrase A local ALSA control write can provide an out-of-range HDMI codec enum value that is used to index `e->texts` before validation, causing a limited out-of-bounds read and possible local DoS without evidence of privilege escalation. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be auto-closed for urgent triage because it is local-only, low severity, read-only OOB before validation, and has no supported LPE, network, or disclosure primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ASoC: codecs: hdac_hdmi: Validate written enum value [ Upstream Commit: 216336418c007c4b44c650acf2fd3d2de5bb81e8 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=216336418c007c4b44c650acf2fd3d2de5bb81e8 Changed files: sound/soc/codecs/hdac_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=216336418c007c4b44c650acf2fd3d2de5bb81e8 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74295 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74295 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:L/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:L/I:N/A:L The Best / paranoid CVSS score: 4.4 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: 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).