CVE-2025-39689
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
05/09/2025
Last modified:
08/09/2025
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
ftrace: Also allocate and copy hash for reading of filter files<br />
<br />
Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds<br />
the pointer to the global tracer hash to its iterator. Unlike the writer<br />
that allocates a copy of the hash, the reader keeps the pointer to the<br />
filter hashes. This is problematic because this pointer is static across<br />
function calls that release the locks that can update the global tracer<br />
hashes. This can cause UAF and similar bugs.<br />
<br />
Allocate and copy the hash for reading the filter files like it is done<br />
for the writers. This not only fixes UAF bugs, but also makes the code a<br />
bit simpler as it doesn&#39;t have to differentiate when to free the<br />
iterator&#39;s hash between writers and readers.
Impact
References to Advisories, Solutions, and Tools
- https://git.kernel.org/stable/c/12064e1880fc9202be75ff668205b1703d92f74f
- https://git.kernel.org/stable/c/3b114a3282ab1a12cb4618a8f45db5d7185e784a
- https://git.kernel.org/stable/c/64db338140d2bad99a0a8c6a118dd60b3e1fb8cb
- https://git.kernel.org/stable/c/a40c69f4f1ed96acbcd62e9b5ff3a596f0a91309
- https://git.kernel.org/stable/c/bfb336cf97df7b37b2b2edec0f69773e06d11955
- https://git.kernel.org/stable/c/c4cd93811e038d19f961985735ef7bb128078dfb
- https://git.kernel.org/stable/c/c591ba1acd081d4980713e47869dd1cc3d963d19
- https://git.kernel.org/stable/c/e0b6b223167e1edde5c82edf38e393c06eda1f13