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CVE PROGRAM SOURCE RECORD6.2 Medium

CVE-2026-6386

Missing large page handling in pmap_pkru_update_range()

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Status
Published
Published
Updated
Assigning organization
freebsd

Description

In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries. The subroutine which handled this failed to take into account the presence of 1GB largepage mappings created using the shm_create_largepage(3) interface. In particular, it would always treat a page directory page entry as pointing to another page table page. The bug can be abused by an unprivileged user to cause pmap_pkru_update_range() to treat userspace memory as a page table page, and thus overwrite memory to which the application would otherwise not have access.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

FreeBSD FreeBSD

Default version status: unknown

  • 15.0-RELEASE to < p6affected
  • 14.4-RELEASE to < p2affected
  • 14.3-RELEASE to < p11affected
  • 13.5-RELEASE to < p12affected

References