Local privilege escalation via perf mapping race
Published Jul 25, 2026 · Updated Jul 25, 2026
Use-after-free in the perf/AUX subsystem of Linux Kernel allows local users to gain elevated code execution through a mapping race. The map_range() path reads rb->aux_pages, rb->aux_nr_pages, and rb->aux_pgoff under only event->mmap_mutex while rb_alloc_aux() changes them under rb->aux_mutex. Two performance events must share one ring buffer through PERF_EVENT_IOC_SET_OUTPUT, allowing a VM_PFNMAP mapping to retain a freed physical frame without refcount protection.
Summary
What happened
Use-after-free in the perf/AUX subsystem of Linux Kernel allows local users to gain elevated code execution through a mapping race. The map_range() path reads rb->aux_pages, rb->aux_nr_pages, and rb->aux_pgoff under only event->mmap_mutex while rb_alloc_aux() changes them under rb->aux_mutex. Two performance events must share one ring buffer through PERF_EVENT_IOC_SET_OUTPUT, allowing a VM_PFNMAP mapping to retain a freed physical frame without refcount protection.
The record
- CVE
- CVE-2026-64300
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-825, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.14
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <0cff05bd2186020f8706233e261016d149cc24db
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <5948aaf64f81f217a25dcc2bf6c0779bca19566c
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <c8b7e113f7b61eef2f017e6329c27c2331058c5a
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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