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CVE-2025-39689

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_…

Published Sep 5, 2025 · updated Oct 15, 2026 · linux linux kernel

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.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 5, 2025 · NIST NVD

    Detected

    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 p

  2. Oct 15, 2026 · NIST NVD

    Updated

    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 p

Affected

  • cpe debian/debian linux11.0
  • cpe linux/linux kernelversion unspecified
  • cpe linux/linux kernel6.17

Sources

  • CVE.orgVulnerability recordCVE-2025-39689

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2025-39689

    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 write

    nvd.nist.gov

References