Bug 2532417 (CVE-2026-89443)

Summary: CVE-2026-89443 kernel: platform/x86: ISST: Validate level in perf mask ioctls
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's platform/x86 ISST module. The `isst_if_get_perf_level_mask()` and `isst_if_get_base_freq_mask()` functions fail to validate a user-provided 'level' parameter. A local attacker could exploit this by providing an invalid 'level' value, leading to an out-of-bounds read from the per-level offset table. This could result in information disclosure or a denial of service (DoS).
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Description OSIDB Bzimport 2026-09-11 22:54:17 UTC 
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.
Comment 1 Keith Grant 2026-09-14 21:41:57 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89443.mbox