CVE-2026-93239

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

N/A
Published: September 24, 2026 at 03:34 PM UTC
Updated: October 19, 2026 at 10:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
N/A
Exploit prediction
EPSS 0.2%

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 pointer from a different parent value.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1d18c47c735e8adfe531fc41fae31e98f86b68fe3.7
Vendor states this is fixed in 08d931a0a850ad16a64f2cd23a19f40795cdbdf7 (fixed)
Vendor states this is fixed in 0f05d95b99164a9ccc4cf4a4920e0ff0228138ad (fixed)
Vendor states this is fixed in 68cbd70795dd8c06e7ccdc4eb0b74c5b180076c3 (fixed)
Vendor states this is fixed in a77644d009dece1104b6fcc6e322b0e4503db0d6 (fixed)
Vendor states this is fixed in b28fe65a36b8209b6adcf2722c7ce974cf9ac8d1 (fixed)
Vendor states this is fixed in 3.7 (unaffected)
Vendor states this is fixed in 6.12.110 (unaffected)
Vendor states this is fixed in 6.18.51 (unaffected)
Vendor states this is fixed in 6.6.157 (unaffected)
Vendor states this is fixed in 7.2.5 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

Quick Info

StatusRECEIVED

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