Soft lockup via unbounded sparse PFN scan
Published Jun 20, 2024 · Updated May 11, 2026
Denial of service in Linux kernel 4.14 through 5.17-rc2 allows local users to cause a soft lockup by initiating a kmemleak scan. kmemleak_scan iterates every PFN through an extremely large node range, repeatedly testing a sparse ZONE_DEVICE hole instead of skipping it. Reachability requires permission to initiate kmemleak scanning and a large ZONE_DEVICE hole, observed when amdkfd registered memory on some AMD APUs; the consequence is prolonged CPU starvation and a watchdog soft lockup.
Summary
What happened
Denial of service in Linux kernel 4.14 through 5.17-rc2 allows local users to cause a soft lockup by initiating a kmemleak scan. kmemleak_scan iterates every PFN through an extremely large node range, repeatedly testing a sparse ZONE_DEVICE hole instead of skipping it. Reachability requires permission to initiate kmemleak scanning and a large ZONE_DEVICE hole, observed when amdkfd registered memory on some AMD APUs; the consequence is prolonged CPU starvation and a watchdog soft lockup.
The record
- CVE
- CVE-2022-48731
- Published
- Jun 20, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 20, 2024CVE 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=4.14
- Affected versionversion=4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 <352715593e81b917ce1b321e794549815b850134
- Affected versionversion=4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 <a5389c80992f0001ee505838fe6a8b20897ce96e
- Affected versionversion=4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 <c10a0f877fe007021d70f9cada240f42adc2b5db
- Affected versionversion=4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 <cebb0aceb21ad91429617a40e3a17444fabf1529
- Affected versionversion=4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 <d3533ee20e9a0e2e8f60384da7450d43d1c63d1a
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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