Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.10.1, < 6.12.77 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/91f3e8d84c89918769e71393f839c9fefadc2580Patch
- https://git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0Patch
- https://git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58bPatch
- https://git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0ePatch
FAQ
What is CVE-2026-23380?
CVE-2026-23380 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_m...
How severe is CVE-2026-23380?
CVE-2026-23380 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-23380?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.