[PATCH net 2/5] iavf: fix PTP use-after-free during reset

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Petr Oros <poros@redhat.com>

Commit 7c01dbfc8a1c5f ("iavf: periodically cache PHC time") introduced a
worker to cache PHC time, but failed to stop it during reset or disable.

This creates a race condition where `iavf_reset_task()` or
`iavf_disable_vf()` free adapter resources (AQ) while the worker is still
running. If the worker triggers `iavf_queue_ptp_cmd()` during teardown, it
accesses freed memory/locks, leading to a crash.

Fix this by calling `iavf_ptp_release()` before tearing down the adapter.
This ensures `ptp_clock_unregister()` synchronously cancels the worker and
cleans up the chardev before the backing resources are destroyed.

Fixes: 7c01dbfc8a1c5f ("iavf: periodically cache PHC time")
Signed-off-by: Petr Oros <poros@redhat.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 86c1964f42e1..c7abd3331e03 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3036,6 +3036,8 @@ static void iavf_disable_vf(struct iavf_adapter *adapter)
 
 	adapter->flags |= IAVF_FLAG_PF_COMMS_FAILED;
 
+	iavf_ptp_release(adapter);
+
 	/* We don't use netif_running() because it may be true prior to
 	 * ndo_open() returning, so we can't assume it means all our open
 	 * tasks have finished, since we're not holding the rtnl_lock here.
@@ -3211,6 +3213,8 @@ static void iavf_reset_task(struct work_struct *work)
 	iavf_change_state(adapter, __IAVF_RESETTING);
 	adapter->flags &= ~IAVF_FLAG_RESET_PENDING;
 
+	iavf_ptp_release(adapter);
+
 	/* free the Tx/Rx rings and descriptors, might be better to just
 	 * re-use them sometime in the future
 	 */
-- 
2.47.1