CVE-2025-40347 describes a deadlock vulnerability in the Linux kernel's enetc network driver. After applying a workaround for err050089, the LS1028A platform experiences RCU stalls on real-time kernels caused by recursive acquisition of the enetc_mdio_lock read lock. The deadlock occurs when enetc_poll acquires the read lock and a higher-priority writer attempts to acquire the same lock, leading to preemption and scheduling issues that cause thread hangs. The vulnerability is addressed by modifying enetc_lock_mdio to prevent recursive lock acquisition, thereby avoiding the deadlock condition.

This vulnerability can cause denial of service through thread hangs and RCU stalls on affected systems using the LS1028A platform with real-time Linux kernels. There is no impact on confidentiality or integrity, but availability is severely affected due to deadlocks in kernel networking code.

A fix is available that adjusts the enetc_lock_mdio function to prevent recursive lock acquisition and thus avoid deadlocks. Users should apply the official Linux kernel patch that resolves this issue. Patch status is not explicitly stated here; verify with the Linux kernel vendor advisory for the exact fixed versions and apply updates accordingly.