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.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 06 Sep 2025 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Sat, 06 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Fri, 05 Sep 2025 17:30:00 +0000

Type Values Removed Values Added
Description 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.
Title ftrace: Also allocate and copy hash for reading of filter files
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-29T05:57:27.158Z

Reserved: 2025-04-16T07:20:57.113Z

Link: CVE-2025-39689

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-09-05T18:15:45.573

Modified: 2025-09-08T16:25:38.810

Link: CVE-2025-39689

cve-icon Redhat

Severity : Important

Publid Date: 2025-09-05T00:00:00Z

Links: CVE-2025-39689 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-09-06T09:01:27Z