Kernel-memory consumption via unreleased kexec FDT buffer
Published Dec 8, 2025 · Updated May 11, 2026
Memory leak in the RISC-V kexec path in Linux 5.19 allows local users to consume kernel memory by reloading or unloading a kernel. elf_kexec_load allocates an FDT buffer with kvmalloc, but the RISC-V cleanup path fails to free it when the loaded image is replaced or discarded. Reaching the path requires CAP_SYS_BOOT and a kernel built with kexec file-loading support; the published record demonstrates unreclaimed memory but no crash.
Summary
What happened
Memory leak in the RISC-V kexec path in Linux 5.19 allows local users to consume kernel memory by reloading or unloading a kernel. elf_kexec_load allocates an FDT buffer with kvmalloc, but the RISC-V cleanup path fails to free it when the loaded image is replaced or discarded. Reaching the path requires CAP_SYS_BOOT and a kernel built with kexec file-loading support; the published record demonstrates unreclaimed memory but no crash.
The record
- CVE
- CVE-2022-50631
- Published
- Dec 8, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Dec 8, 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=5.19
- Affected versionversion=6261586e0c91db14c34f894f4bc48f2300cff1d4 <96df59b1ae23f5c11698c3c2159aeb2ecd4944a4
- Affected versionversion=6261586e0c91db14c34f894f4bc48f2300cff1d4 <c66ad198b6497dee8f45d7ed5c03629c4525c7d0
- Affected versionversion=6261586e0c91db14c34f894f4bc48f2300cff1d4 <dc387c34d8dd10b02a333df098f8fd9bba177a45
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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.
Weakness, pattern, technique
No sourced classifications are available.
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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