In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs

When a VMA is split (e.g., by partial munmap or MAP_FIXED), the kernel
calls vm_ops->close on each portion. For trace buffer mappings, this
results in ring_buffer_unmap() being called multiple times while
ring_buffer_map() was only called once.

This causes ring_buffer_unmap() to return -ENODEV on subsequent calls
because user_mapped is already 0, triggering a WARN_ON.

Trace buffer mappings cannot support partial mappings because the ring
buffer structure requires the complete buffer including the meta page.

Fix this by adding a may_split callback that returns -EINVAL to prevent
VMA splits entirely.
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8094-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8094-2 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 23 Dec 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Mon, 22 Dec 2025 16:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs When a VMA is split (e.g., by partial munmap or MAP_FIXED), the kernel calls vm_ops->close on each portion. For trace buffer mappings, this results in ring_buffer_unmap() being called multiple times while ring_buffer_map() was only called once. This causes ring_buffer_unmap() to return -ENODEV on subsequent calls because user_mapped is already 0, triggering a WARN_ON. Trace buffer mappings cannot support partial mappings because the ring buffer structure requires the complete buffer including the meta page. Fix this by adding a may_split callback that returns -EINVAL to prevent VMA splits entirely.
Title tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-22T16:14:06.466Z

Reserved: 2025-12-16T14:48:05.296Z

Link: CVE-2025-68329

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-22T17:16:00.580

Modified: 2025-12-23T14:51:52.650

Link: CVE-2025-68329

cve-icon Redhat

Severity : Low

Publid Date: 2025-12-22T00:00:00Z

Links: CVE-2025-68329 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.