net: ravb: serialize PTP clock teardown

Overview

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

net: ravb: serialize PTP clock teardown

ravb_ptp_interrupt() can race with ravb_ptp_stop() and pass the clock to ptp_clock_event() while ptp_clock_unregister() is freeing it. This can lead to a use-after-free.

Use READ_ONCE() and WRITE_ONCE() for lockless access to the clock pointer. Atomically detach it with xchg() before disabling PTP interrupts, then synchronize all IRQs which can invoke ravb_ptp_interrupt() before unregistering the detached clock.

A handler which read the old pointer completes before the clock is unregistered, while later handlers read NULL and skip the event.

Affected

• Linux >= a0d2f20650e81407d8e51ad2cbdc492861c74e9c < b917f37bfcce919a969d66a044580a95b11df31c
• Linux >= a0d2f20650e81407d8e51ad2cbdc492861c74e9c < 695acb5534a9e366efb47b40c7487fc56488b09b
• Linux >= a0d2f20650e81407d8e51ad2cbdc492861c74e9c < 67a82e6f886beed0de8f8da08bb767e68fba952d
• Linux >= a0d2f20650e81407d8e51ad2cbdc492861c74e9c < 66b50c31419e7946e9aa325a468ad9b64c961a25
• Linux >= a0d2f20650e81407d8e51ad2cbdc492861c74e9c < 1cb9663789c5b7a12fcd419fcca6d6254c398252
• Linux 4.2

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · updated 2026-09-14 · vex