Kernel Vulnerability in Linux Affecting SMC91x Products

CVE-2025-71132

What is CVE-2025-71132?

A vulnerability exists in the Linux kernel related to the SMC91x network driver when built with PREEMPT_RT. This flaw leads to improper restoration of interrupt request (IRQ) states, resulting in potential disruptions in system operations. The failure arises from the smc_special_trylock function disabling IRQs without a corresponding mechanism to restore them during preemption, which could lead to lock-ups or unhandled conditions in low-level scheduling. The issue has been addressed by replacing smc_special_trylock with a safer spin_trylock_irqsave function, further enhancing the robustness of the kernel in managing IRQs effectively.

References