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

No advisories yet.

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 : Received

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

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

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.