Linux Kernel PCI Deadlock Vulnerability in SR-IOV Configuration

A deadlock vulnerability has been identified in the Linux kernel's PCI subsystem, specifically within the SR-IOV (Single Root I/O Virtualization) configuration process. The issue arises because the sysfs 'sriov_numvfs_store' function acquires the device lock before the configuration space access lock. This can lead to a deadlock when 'sriov_numvfs_store' is called after 'pci_dev_lock', which waits for the device lock, creating a circular dependency.

Impact

Exploitation of this vulnerability can lead to a deadlock situation, causing the system to hang or become unresponsive while waiting for locks to be released.

Remediation

The vulnerability has been addressed by reversing the order in which locks are acquired, ensuring that the device lock is obtained before the configuration space access lock. Users should apply the latest patches available in the Linux kernel to mitigate this issue.