What’s Vulnerable › Vulnerabilities

CVE-2023-54139: tracing/user_events: Ensure write index cannot be negative

• Severity: high (CVSS 7.8 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: 2025-12-24 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: tracing/user_events: Ensure write index cannot be negative The write index indicates which event the data is for and accesses a per-file array. The index is passed by user processes during write() calls as the first 4 bytes. Ensure that it cannot be negative by returning -EINVAL to prevent out of bounds accesses. Update ftrace self-test to ensure this occurs properly.

Affected products

• Linux kernel: 5.18 — fixed in 6.4

How to fix

Upgrade to a fixed version: Linux kernel 6.4. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0489c2b2c3104b89f078dbcec8c744dfc157d3e9
• https://git.kernel.org/stable/c/4fe46b5adf18e3dc606e62c9e6a0413398a17572
• https://git.kernel.org/stable/c/cd98c93286a30cc4588dfd02453bec63c2f4acf4
• https://git.kernel.org/stable/c/fa7f2f5d1739452280c22727c4384a52b72ab5de

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