From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53205][MODERATE REGULAR] accel/ivpu: Add bounds checks for firmware log indices Date: Thu, 25 Jun 2026 20:33:54 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53205 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: 2 X-AL-KERNEL-Commit: 5961c703414048f46818be8bbb11075a9a63fb4e List-Id: CVE: CVE-2026-53205 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: accel/ivpu: Add bounds checks for firmware log indices Commit: 5961c703414048f46818be8bbb11075a9a63fb4e Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5961c703414048f46818be8bbb11075a9a63fb4e Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53205 Analysis date: Thu, 25 Jun 2026 20:33:54 -0400 ActionableScore: 4 ActionableScore lower bound: 2 Actionable bucket: Borderline manual review recommended / ordinary Moderate unless firmware or local trigger is credible Manual review required: YES Summary: A firmware-supplied out-of-bounds log index in the Intel ivpu driver can cause invalid buffer reads during firmware log printing, with possible local DoS and limited diagnostic-output information disclosure depending on device and permission exposure. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53205 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53205 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-2026-53205 MODERATE CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H';CWE-125;CWE-129;*CWE-20;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L';BEST CVSS score: '5.3';DESCR 'An out of bounds read in the Intel ivpu firmware log path may occur because firmware supplied read_index and write_index values are used as offsets into the log data buffer without sufficient bounds validation. If a faulty or malicious firmware instance places read_index or write_index outside data_size, fw_log_print_buffer can calculate invalid ranges and read past the firmware log buffer while printing diagnostic output. For the CVSS the PR:L is used for the paranoid score because triggering requires local access to the ivpu device or diagnostic path and influence over firmware log activity, but not necessarily full host administrator privileges in all deployments. The issue is not network reachable. Impact is mainly denial of service via invalid memory access, with limited confidentiality risk if adjacent memory is exposed through the log output. YES REQUIRES MANUAL CHECK';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline manual review recommended / ordinary Moderate unless firmware or local trigger is credible (with actual score 3) SKIP CVE-2026-53205 SKIP The Fixes patch not applied yet, so unlikely that actual: 1fc1251149a76d3b75d7f4c94d9c4e081b7df6b4 YES NO NO unknown MAYBE WRITE OOB SIMPLEFIX LOG LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 ActionableScoreLower=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 4 * Final recommended bucket: **Borderline manual review recommended / ordinary Moderate unless firmware or local trigger is credible** ## 2. Signal breakdown Conservative signals: * Firmware-mediated external influence: +1. The invalid indices come from firmware-controlled log metadata. * Privileged kernel/device-management path: +1. The bug is in an accelerator driver firmware log path running in trusted kernel context. * Confidentiality impact plausible: +1. An OOB read during log printing could potentially expose adjacent memory through diagnostic output. * Rare AND difficult-to-reach subsystem/configuration: -1. This requires Intel ivpu hardware and the affected firmware log path. Paranoid additional signals: * Local unprivileged trigger: +1. Some deployments may allow non-root users to access accelerator workloads or paths that indirectly cause firmware log activity. * Reliable kernel crash / strong DoS: +1. If the OOB index reaches unmapped or invalid memory during log printing, a kernel fault is plausible. Not counted: * No generic strong memory corruption. The patch indicates OOB read or invalid offset use, not OOB write, UAF, double-free, or controlled overwrite. * No remote/network reachability. * No strong LPE primitive demonstrated. ## 3. Reachability analysis The direct source of invalid indices is firmware, not a network packet or ordinary syscall argument. A local user may be able to influence firmware activity through accelerator workloads, but reliable control of `read_index` or `write_index` is not demonstrated by the patch. Access to the actual log printing path may also depend on debugfs or driver diagnostics permissions, which often require elevated privileges. Namespaces do not obviously make this broadly reachable unless the ivpu device is delegated into a container. ## 4. Severity interpretation This behaves more like a low-to-moderate firmware-mediated OOB read than an Important-class kernel memory corruption issue. Theoretical impact includes kernel crash and limited memory disclosure through logs, but the patch does not support arbitrary write, object lifetime corruption, or a credible privilege escalation primitive. Manual review is useful mainly to confirm who can trigger log printing and whether unprivileged accelerator workloads can influence firmware log indices. ## 5. One-sentence report phrase A firmware-supplied out-of-bounds log index in the Intel ivpu driver can cause invalid buffer reads during firmware log printing, with possible local DoS and limited diagnostic-output information disclosure depending on device and permission exposure. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: explicit OOB buffer access exists in a firmware-fed kernel driver path, but exploitation appears constrained and no strong memory corruption or LPE primitive is shown. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: accel/ivpu: Add bounds checks for firmware log indices Commit: 5961c703414048f46818be8bbb11075a9a63fb4e Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5961c703414048f46818be8bbb11075a9a63fb4e Commit description: Add validation that read and write indices in the firmware log buffer are within valid bounds (< data_size) before using them. If out-of-bounds indices are encountered (from firmware), clamp them to safe values instead of proceeding with invalid offsets. This prevents potential out-of-bounds buffer access when firmware supplies invalid log indices. Fixes: 1fc1251 ("accel/ivpu: Refactor functions in ivpu_fw_log.c") Cc: stable@vger.kernel.org # v6.18+ Signed-off-by: Andrzej Kacprowski Reviewed-by: Karol Wachowski Signed-off-by: Karol Wachowski Link: https://patch.msgid.link/20260529115842.135378-1-andrzej.kacprowski@linux.intel.com Signed-off-by: Greg Kroah-Hartman Changed files: drivers/accel/ivpu/ivpu_fw_log.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=5961c703414048f46818be8bbb11075a9a63fb4e ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53205 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53205 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:L/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/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: 2 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).