PT-2026-34242 · Freebsd · Freebsd
Published
2026-04-22
·
Updated
2026-04-22
·
CVE-2026-6386
None
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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.
Incorrect Permission
Improper Privilege Management
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Related Identifiers
Affected Products
Freebsd