From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53202][IMPORTANT] accel/ivpu: Fix signed integer truncation in IPC receive Date: Mon, 29 Jun 2026 10:09:38 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53202 X-AL-KERNEL-Priority: IMPORTANT X-AL-KERNEL-Severity: IMPORTANT X-AL-KERNEL-Base-Severity: IMPORTANT X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 8 X-AL-KERNEL-ActionableScore-Lower: 6 X-AL-KERNEL-Commit: 4788556d4dd9d717037e385de178974e9649231d List-Id: CVE: CVE-2026-53202 Priority: IMPORTANT AL-KERNEL base severity: IMPORTANT KPANIC flag: YES Patch: accel/ivpu: Fix signed integer truncation in IPC receive Commit: 4788556d4dd9d717037e385de178974e9649231d Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4788556d4dd9d717037e385de178974e9649231d Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53202 Analysis date: Mon, 29 Jun 2026 10:09:38 -0400 ActionableScore: 8 ActionableScore lower bound: 6 Actionable bucket: Strong Important candidate / Actionable Moderate at minimum Manual review required: YES Summary: A signed integer truncation in the ivpu IPC receive path can turn firmware supplied data_size into an oversized memcpy length, causing kernel stack buffer overflow with at least local DoS impact and plausible privilege escalation when a local user can reach the accelerator IPC path. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53202 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53202 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: IMPORTANT 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-2026-53202 IMPORTANT CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-681;CWE-190;CWE-121;*CWE-787;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';BEST CVSS score: '7.8';DESCR 'A signed integer truncation in the ivpu IPC receive path can convert a firmware supplied data_size value into a negative signed int and then back into a very large unsigned copy size. This can make memcpy operate with an oversized length and overflow a kernel stack buffer. For the CVSS the PR:L is used because practical triggering is expected to require a local user or process that can interact with the ivpu accelerator device or influence the firmware IPC path. The issue is not network reachable. Impact is at least local denial of service via kernel crash and may allow privilege escalation because the primitive is kernel stack memory corruption rather than a simple NULL dereference or warning.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 8) SKIP CVE-2026-53202 SKIP The Fixes patch not applied yet, so unlikely that actual: 3b434a3445fff3149128db0169da864d67057325 YES NO NO unknown MAYBE OOB SIMPLEFIX KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=8 ActionableScoreLower=6 ## 1. ActionableScore * Conservative score: 6 * Paranoid score: 8 * Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**:: ## 2. Signal breakdown * Firmware-mediated external influence: +1. The corrupted size field is firmware supplied. * Local unprivileged trigger: +1. Practical triggering likely requires a local process able to use the ivpu accelerator device. * Generic memory corruption: +2 in paranoid scoring. The bug can produce an oversized memcpy into a kernel stack buffer. * Constrained corruption uncertainty: -1 in conservative scoring. The overwrite path is driver local and depends on firmware IPC behavior, so direct attacker control over payload and reliability is not fully demonstrated. * Privilege escalation plausible: +2 paranoid / +1 conservative. Kernel stack corruption can plausibly become LPE, but the practical control path is firmware mediated. * Reliable kernel crash / strong DoS: +1. Oversized memcpy into stack memory can realistically crash the kernel. * Privileged kernel/device-management memory corruption path: +1. The corruption occurs in a trusted accelerator driver IPC path. * Rare or hardware-specific exposure: -1. The affected path requires Intel ivpu hardware and enabled driver support. * Confidentiality impact plausible: +1 paranoid. Kernel memory corruption may allow disclosure in a developed exploit. * Integrity impact plausible: +1 paranoid. Kernel stack overwrite makes integrity impact technically plausible. ## 3. Reachability analysis The bug is not network reachable. The immediate input is firmware supplied IPC data, so external influence is firmware mediated rather than directly remote. A local user with access to the accelerator device may be able to trigger the affected IPC receive path, depending on device node permissions and deployment policy. If the device is exposed through render or accelerator group access, PR:L is more appropriate than PR:H. Containers and delegated device access can also lower practical privilege requirements if the device node is passed through. ## 4. Severity interpretation This is stronger than an ordinary Moderate because the patch context explicitly describes a stack buffer overflow, not just a NULL dereference or warning. Realistic exploitability is less certain because attacker control is indirect and firmware mediated, but the primitive is still kernel stack memory corruption in a privileged driver path. Conservative handling is Actionable Moderate. Paranoid handling is Strong Important candidate due to plausible LPE from stack corruption. ## 5. One-sentence report phrase A signed integer truncation in the ivpu IPC receive path can turn firmware supplied data_size into an oversized memcpy length, causing kernel stack buffer overflow with at least local DoS impact and plausible privilege escalation when a local user can reach the accelerator IPC path. ## 6. Manual review recommendation MANUAL CHECK REQUIRED. The patch describes kernel stack memory corruption from an oversized memcpy, and the practical risk depends on device permissions, firmware IPC controllability, and exploitability of the stack overwrite. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: accel/ivpu: Fix signed integer truncation in IPC receive Commit: 4788556d4dd9d717037e385de178974e9649231d Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4788556d4dd9d717037e385de178974e9649231d Commit description: Fix potential buffer overflow where firmware-supplied data_size is cast to signed int before being used in min_t(). Large unsigned values (>= 0x80000000) become negative, causing unsigned wraparound and oversized memcpy operations that can overflow the stack buffer. Change min_t(int, ...) to min() as both values are unsigned and can be handled by min() without explicit cast. Fixes: 3b434a3 ("accel/ivpu: Use threaded IRQ to handle JOB done messages") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Andrzej Kacprowski Reviewed-by: Karol Wachowski Signed-off-by: Karol Wachowski Link: https://patch.msgid.link/20260601161643.229342-1-andrzej.kacprowski@linux.intel.com Signed-off-by: Greg Kroah-Hartman Changed files: drivers/accel/ivpu/ivpu_ipc.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=4788556d4dd9d717037e385de178974e9649231d ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53202 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53202 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:H/I:H/A:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.8 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: 6 Paranoid ActionableScore: 8 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: IMPORTANT KPANIC detected for this report: YES Published priority for this report (same as in Subject): IMPORTANT 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).