Riskcovery

CVE-2026-23380

tracing: Fix WARN_ON in tracing_buffers_mmap_close

State
Published
Severity
Not scored
Published
Mar 25, 2026
Updated
May 11, 2026
Reserved
Jan 13, 2026

Read the record on cve.org

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to before 91f3e8d84c89918769e71393f839c9fefadc2580Affected
  • cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to before cdd96641b64297a2db42676f051362b76280a58bAffected
  • cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to before b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0Affected
  • cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to before e39bb9e02b68942f8e9359d2a3efe7d37ae6be0eAffected
LinuxLinux
  • 6.10Affected
  • before 6.10Not affected
  • 6.12.77 through 6.12.*Not affected
  • 6.18.17 through 6.18.*Not affected
  • 6.19.7 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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