CVE-2026-93239

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

arm64: mm: Fix the lockless page-table walk in show_pte()

show_pte() walks page tables locklessly and can run with interrupts

enabled. A concurrent teardown can free a table page while it is being

walked. It can also clear a parent entry after show_pte() checked it; the

regular pXd_offset() helpers then reread the cleared entry and can derive a

bogus lower-level pointer and fault again.

Use the lockless offset helpers with the saved parent entries, as

gup_fast() does, and pass the saved PMD to pte_offset_map().

For task page tables, arm64 selects MMU_GATHER_RCU_TABLE_FREE. Disable

local interrupts around the walk to hold off RCU-deferred table frees and

block the tlb_remove_table_sync_one() IPI until the walk is finished.

Place the IRQ guard after the header print. This does not make the output a

consistent snapshot, but prevents the task page-table walk from

dereferencing a released table page or deriving a point

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References