The FIOSSHMLPGCNF ioctl(2) operation configures the page size for a largepage shared memory object. This is intended to be used immediately after creating the object, before any memory is allocated for the object. The handler checked whether a page size had already been configured without holding the rangelock. Two concurrent callers could both observe an unconfigured object and set conflicting page sizes, leaving the object in an inconsistent state.

An unprivileged local user can exploit this race to escalate privileges.

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History

Wed, 26 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 26 Aug 2026 08:00:00 +0000

Type Values Removed Values Added
First Time appeared Freebsd
Freebsd freebsd
Vendors & Products Freebsd
Freebsd freebsd

Wed, 26 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Description The FIOSSHMLPGCNF ioctl(2) operation configures the page size for a largepage shared memory object. This is intended to be used immediately after creating the object, before any memory is allocated for the object. The handler checked whether a page size had already been configured without holding the rangelock. Two concurrent callers could both observe an unconfigured object and set conflicting page sizes, leaving the object in an inconsistent state. An unprivileged local user can exploit this race to escalate privileges.
Title TOCTOU race in POSIX shared memory large page configuration
Weaknesses CWE-367
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cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-08-26T18:36:23.194Z

Reserved: 2026-06-29T01:40:17.499Z

Link: CVE-2026-58094

cve-icon Vulnrichment

Updated: 2026-08-26T18:36:20.404Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-08-26T06:16:26.350

Modified: 2026-08-26T19:16:51.350

Link: CVE-2026-58094

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-26T21:00:12Z

Weaknesses