[PATCH 6.18 082/333] iavf: fix PTP use-after-free during reset

Greg Kroah-Hartman
2026-03-17T17:10:15Z

From: Petr Oros <poros@redhat.com>

[ Upstream commit efc54fb13d79117a825fef17364315a58682c7ec ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 53a0366fbf998..3625c70bc3292 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3040,6 +3040,8 @@ 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.
@@ -3215,6 +3217,8 @@ 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
*/
--
2.51.0