Local privilege escalation via SMC waitqueue race
Published Jun 20, 2024 · Updated Aug 5, 2026
An SMC waitqueue race in affected Linux kernel releases allows local users to crash the kernel during fallback from SMC to TCP. The fallback path privately moves epoll entries from smc socket->wq to clcsock->wq while their owners continue synchronizing through the original waitqueue lock, allowing concurrent removal during iteration. An unprivileged local process can create an SMC socket, attach epoll waiters, and race fallback wakeups; successful memory reuse also enables kernel reads, writes, or code execution.
Summary
What happened
An SMC waitqueue race in affected Linux kernel releases allows local users to crash the kernel during fallback from SMC to TCP. The fallback path privately moves epoll entries from smc socket->wq to clcsock->wq while their owners continue synchronizing through the original waitqueue lock, allowing concurrent removal during iteration. An unprivileged local process can create an SMC socket, attach epoll waiters, and race fallback wakeups; successful memory reuse also enables kernel reads, writes, or code execution.
The record
- CVE
- CVE-2022-48721
- Published
- Jun 20, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 20, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=2153bd1e3d3dbf6a3403572084ef6ed31c53c5f0 <341adeec9adad0874f29a0a1af35638207352a39
- Affected versionversion=2153bd1e3d3dbf6a3403572084ef6ed31c53c5f0 <504078fbe9dd570d685361b57784a6050bc40aaa
- Affected versionversion=5.10.84 <5.11
- Affected versionversion=5.15.7 <5.15.22
- Affected versionversion=5.16
- Affected versionversion=5.4.164 <5.5
- Affected versionversion=d6e981ec9491be5ec46d838b1151e7edefe607f5
- Affected versionversion=fb92e025baa73e99250b79ab64f4e088d2888993 <0ef6049f664941bc0f75828b3a61877635048b27
- Affected versionversion=ff6eeb627898c179aac421af5d6515d3f50b84df
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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