Linux Kernel DRM Imagination Soft Reset Deadlock Vulnerability

A deadlock issue has been identified in the Linux kernel's handling of soft resets for DRM Imagination devices. This vulnerability arises because the soft reset sequence is executed from a threaded IRQ handler, which prevents the use of the 'disable_irq()' function that waits for IRQ handlers to complete. Instead, 'disable_irq_nosync()' should be used during a soft reset to avoid this deadlock. This issue affects the Linux kernel stable tree.

Impact

The vulnerability can lead to a deadlock situation where the soft reset process is halted, potentially causing disruptions in the normal operation of the affected DRM Imagination devices.

Reproduction

The vulnerability can be reproduced by initiating a soft reset sequence for a DRM Imagination device while the IRQ handler is still processing. This will create a deadlock, as the 'disable_irq()' function cannot be used to properly manage the IRQ state.

Remediation

Users can apply the latest patch available in the Linux kernel stable tree, which modifies the soft reset handling to use 'disable_irq_nosync()' instead of 'disable_irq()'.