CVE-2026-97963

In the Linux kernel, the following vulnerability has been resolved:

net: stmmac: initialize ptp_lock at probe time

priv->ptp_lock is only initialized in stmmac_ptp_register(), which runs
during __stmmac_open(). However, the lock is also used while the
interface is down and has never been opened: tc_taprio_configure()
invokes the PTP gettime64() callback to compute the EST base time when
offloading a TAPRIO schedule, and stmmac_get_time() takes
priv->ptp_lock. Using an uninitialized rwlock is undefined behaviour.
Move the rwlock_init() to __stmmac_dvr_probe(), together with the other
private locks, so that ptp_lock is always valid regardless of the
interface state.