CVE Catalog

CVE-2026-93239

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel on arm64, show_pte() performs a lockless page-table walk that can dereference a freed table page or derive a bogus pointer during concurrent teardown. The fix uses lockless offset helpers with saved parent entries and disables local interrupts around the walk.

Risk Assessment

May cause kernel errors, panics, or exposure of incorrect memory mapping information on arm64 systems, affecting system stability and security.

Recommendation

Update the Linux kernel to a version containing the arm64 mm fix. In production arm64 environments, schedule the update in the nearest maintenance window.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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 pointer from a different parent value.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS