Linux Kernel EUVD-2026-39313

The ptp_ocp kernel driver manages Open Compute Platform Precision Time Protocol hardware, exposing hardware timestamping pins as kernel PTP clock devices. Commit a60fc3294a37 reworked ptp_clock_unregister() to call ptp_disable_all_events(), which reconfigures EXTTS-capable pins during unregistration. The bug arises because ptp_ocp_detach() - the driver teardown path - deallocates pin resources prior to invoking ptp_clock_unregister(), creating a use-after-free when the unregister path dereferences those already-freed structures. A secondary SMP race condition exists where an IRQ handler on a sibling CPU core can fire between hardware shutdown and device unregistration; the fix addresses this with synchronize_irq(). CWE-401 (Missing Release of Memory after Effective Lifetime) is assigned, though the described mechanism is more precisely a use-after-free (CWE-416); this CWE discrepancy does not affect remediation. Affected CPEs: cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* (versions introduced by a60fc3294a37) and cpe:2.3:o:linux:linux_kernel:7.1:rc1 through rc7.