tracing: Hold trace_types_lock when resetting last boot data from readers

Summary

In the Linux kernel, the following vulnerability has been resolved: tracing: Hold trace_types_lock when resetting last boot data from readers update_last_data_if_empty() is called from tracing_open() with O_TRUNC, tracing_read_pipe() and tracing_buffers_read() without trace_types_lock. Two readers can both pass the LAST_BOOT test and free module_delta twice, and a module notifier can update module_delta while it is being freed. Take trace_types_lock in those paths and keep the callers that already hold it on an unlocked variant.

Remediation

1. Inventory every Linux Linux deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Referencehttps://git.kernel.org/stable/c/92b69f6db640dadc0851762ee2e12db99f083cad
• Referencehttps://git.kernel.org/stable/c/d6d991afe775ab7fcf89523a2502b7ca3be56ffd
• Referencehttps://git.kernel.org/stable/c/1f06cfe0b60a878619d1d8efe1cd0f515b7dc2aa
• Referencehttps://git.kernel.org/stable/c/5a6bd62f09147b49b31fd19d4eba122cb5f941a1