CVE Catalog

CVE-2025-38579

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

6th percentile - higher than 6% of all known CVEs

Summary

In the f2fs filesystem in the Linux kernel, KMSAN detected use of uninitialized values in the extent_info structure. The get_read_extent_info() function initializes only three fields (fofs, blk, len), leaving others uninitialized, leading to undefined behavior during extent merging.

Risk Assessment

Use of uninitialized data can lead to unpredictable filesystem behavior, including data corruption or kernel crashes.

Recommendation

Apply the Linux kernel patch that zero-initializes the extent_info structure before population to ensure all fields are initialized.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix KMSAN uninit-value in extent_info usage KMSAN reported a use of uninitialized value in `__is_extent_mergeable()` and `__is_back_mergeable()` via the read extent tree path. The root cause is that `get_read_extent_info()` only initializes three fields (`fofs`, `blk`, `len`) of `struct extent_info`, leaving the remaining fields uninitialized. This leads to undefined behavior when those fields are accessed later, especially during extent merging. Fix it by zero-initializing the `extent_info` struct before population.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS