Local service interruption via TCP sysctl race
Published Feb 26, 2025 · Updated May 11, 2026
A race condition in the Linux kernel TCP stack allows local users to interrupt service through concurrent sysctl changes. The TCP readers in include/net/tcp.h and net/ipv4/tcp_output.c access sysctl_tcp_slow_start_after_idle without READ_ONCE while it can change concurrently. Exploitation requires low-privileged local access and a high-complexity race; the bounded reported consequence is availability loss.
Summary
What happened
A race condition in the Linux kernel TCP stack allows local users to interrupt service through concurrent sysctl changes. The TCP readers in include/net/tcp.h and net/ipv4/tcp_output.c access sysctl_tcp_slow_start_after_idle without READ_ONCE while it can change concurrently. Exploitation requires low-privileged local access and a high-complexity race; the bounded reported consequence is availability loss.
The record
- CVE
- CVE-2022-49572
- Published
- Feb 26, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-362, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 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=2.6.18
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <0e3f82a03ec8c3808e87283e12946227415706c9
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <369d99c2b89f54473adcf9acdf40ea562b5a6e0e
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <3b26e11b07a09b31247688bec61e2925d4a571b6
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <41aeba4506f6b70ec7500c6fe202731a4ba29fe5
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <4845b5713ab18a1bb6e31d1fbb4d600240b8b691
- Affected versionversion=35089bb203f44e33b6bbb6c4de0b0708f9a48921 <68b6f9506747d507c7bfa374d178929b4157e8c6
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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