CVE-2022-49630: tcp: Fix a data-race around sysctl_tcp_ecn_fallback.

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix a data-race around sysctl_tcp_ecn_fallback. While reading sysctl_tcp_ecn_fallback, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader.

Affected products

Linux kernel: from 4.2 before 5.15.56; from 5.16 before 5.18.13; 5.19-rc1, 5.19-rc2, 5.19-rc3, 5.19-rc4, 5.19-rc5, 5.19-rc6 — fixed in 5.15.56, 5.18.13

How to fix

Upgrade to a fixed version: Linux kernel 5.15.56, 5.18.13. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/12b8d9ca7e678abc48195294494f1815b555d658
https://git.kernel.org/stable/c/1ec3d6c2626ee6e1b36b7bd006873a271406ba61
https://git.kernel.org/stable/c/8bcf7339f2cf70ea4461df6ea045d1aadfabfa11

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