CVE-2025-68329 — tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs
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 mun…
Published: 2025-12-22 · CVSS: Unscored
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7