CVE Catalog

CVE-2025-39689

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

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

Summary

In the Linux kernel ftrace subsystem, readers of set_ftrace_filter and set_ftrace_notrace files use a pointer to the global hash instead of a copy. After releasing locks, the global hash can be updated, leading to use-after-free and similar bugs.

Risk Assessment

UAF can lead to system crashes, potential arbitrary code execution, or information disclosure.

Recommendation

Apply the Linux kernel patch that allocates and copies the hash for readers of filter files, similar to writers.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ftrace: Also allocate and copy hash for reading of filter files Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds the pointer to the global tracer hash to its iterator. Unlike the writer that allocates a copy of the hash, the reader keeps the pointer to the filter hashes. This is problematic because this pointer is static across function calls that release the locks that can update the global tracer hashes. This can cause UAF and similar bugs. Allocate and copy the hash for reading the filter files like it is done for the writers. This not only fixes UAF bugs, but also makes the code a bit simpler as it doesn't have to differentiate when to free the iterator's hash between writers and readers.

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