Local denial of service via swap-in retry loop
Published Jul 9, 2025 · Updated May 11, 2026
Improper locking in Linux kernel 6.14 through 6.15.4 and 6.16-rc1 through 6.16-rc3 allows local users to cause a soft lockup. In the shmem mTHP swap-in path, an order-0 folio already in the swap cache makes swapcache_prepare return EEXIST, but shmem_swap_alloc_folio retries indefinitely. Exploitation requires local workload execution plus enabled 64 kB mTHP, active swap, and memory pressure, and it can leave a CPU unresponsive for hundreds of seconds.
Summary
What happened
Improper locking in Linux kernel 6.14 through 6.15.4 and 6.16-rc1 through 6.16-rc3 allows local users to cause a soft lockup. In the shmem mTHP swap-in path, an order-0 folio already in the swap cache makes swapcache_prepare return EEXIST, but shmem_swap_alloc_folio retries indefinitely. Exploitation requires local workload execution plus enabled 64 kB mTHP, active swap, and memory pressure, and it can leave a CPU unresponsive for hundreds of seconds.
The record
- CVE
- CVE-2025-38241
- Published
- Jul 9, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 9, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1dd44c0af4fa1e80a4e82faa10cbf5d22da40362 <1283dfc1e0cd52cf525c2cb1b59a6f9183aab7ca
- Affected versionversion=1dd44c0af4fa1e80a4e82faa10cbf5d22da40362 <a05dd8ae5cbb1cb45f349922cfea4f548a5e5d6f
- Affected versionversion=6.14
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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