CVE-2026-89443

Received Received - Intake

Buffer Overflow in Linux Kernel SST-PP

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: platform/x86: ISST: Validate level in perf mask ioctls isst_if_get_perf_level_mask() and isst_if_get_base_freq_mask() use the user-provided level as an index into perf_levels[] via _read_pp_level_info() and _read_bf_level_info(), but neither helper validates it first. The adjacent level-info helpers reject levels above max_level before reading the same per-level register block. Add the same bounds checks to the mask helpers, and reject disabled SST-PP levels in isst_if_get_perf_level_mask() to match isst_if_get_perf_level_info(). This prevents out-of-bounds reads from the per-level offset table on invalid ioctl input.

CVSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-09-12

AI Q&A

2026-09-12

EPSS Evaluated

N/A

NVD

CVE-2026-89443

EUVD

EUVD-2026-76349

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves insufficient validation of user-provided input in certain platform/x86 ISST (Intel Speed Select Technology) ioctl operations. Specifically, functions like isst_if_get_perf_level_mask() and isst_if_get_base_freq_mask() use the user-supplied level parameter as an index without checking if it is within valid bounds.

Detection Guidance

This vulnerability is specific to the Linux kernel's ISST (Intel Speed Select Technology) perf mask ioctls. Detection requires checking kernel logs for related errors or examining kernel source code for unvalidated user input in the affected functions. No direct network detection commands are applicable.

Impact Analysis

An attacker with local access could exploit this to trigger out-of-bounds reads from kernel memory by providing invalid ioctl input. This may lead to system crashes, information leaks, or privilege escalation depending on the kernel memory accessed.

Mitigation Strategies

Update your Linux kernel to the latest patched version where this vulnerability is resolved. Monitor kernel security advisories for updates. If immediate patching is not possible, restrict access to the affected ioctl interfaces or disable SST-PP features as a temporary workaround.

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