Linux Kernel Vulnerability in Fork Process Handling

CVE-2026-99217

What is CVE-2026-99217?

A vulnerability exists in the Linux kernel where a failed fork operation can lead to deadlocks due to improper file handling. When a fork fails while another thread attempts to close a BPF link file descriptor, it causes a deadlock scenario. This occurs because the system holds specific locks while executing close operations, which disrupts normal operations and blocks all subsequent fork actions. The issue arises in the cleanup sequence of the copy_process function, necessitating a reordering of operations to ensure safe management of resources. The fix involves releasing the child's file references post-fork cancellation to prevent these complications, enhancing overall stability for concurrent processes.

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