Linux Kernel Driver Core Deferred Probe Interaction Vulnerability

A vulnerability in the Linux kernel's driver core related to the handling of deferred device probing has been addressed. The issue arose when mounting NFS root filesystems, which timed out due to the deferred_probe_timeout setting. This timeout interfered with the ip_auto_config initialization call, causing delays in network interface availability. The problem was linked to the interaction between the wait_for_device_probe function and the deferred_probe_timeout, leading to either a boot process hang or a blockage of the kernel initialization process. The vulnerability has been resolved by reverting changes that attempted to synchronize the device probing with the timeout, which had inadvertently introduced deadlocks and delays in the boot process.

Impact

The vulnerability could cause NFS root filesystem mounts to time out, disrupt the boot process, and lead to deadlocks or prolonged delays in kernel initialization.