firmware: arm_scmi: Quiesce notifications before teardown

scmi_notification_exit() clears and releases the notification instance,
but transport callbacks can still deliver incoming notifications until
the TX/RX channels are freed. During remove, an RX interrupt in that
window can enter scmi_notify() while notification state is being torn
down and then dereference freed memory. The same ordering exists on the
probe error path after notification initialization.

The notification late-init worker has a separate lifetime issue: protocol
event registration queues ni->init_work on the system workqueue, so
destroying ni->notify_wq does not drain that work. If the devres group is
released while init_work is still pending or running, the late-init worker
can dereference the freed notification instance.

Quiesce the notification core before TX/RX channels are torn down, then
clean up the channels before releasing the notification core resources.
Use disable_work_sync() so future late-init queueing is rejected and any
already queued or running late-init work has completed before channel
teardown starts.

Fixes: 1e7cbfaa66d3 ("firmware: arm_scmi: Free mailbox channels if probe fails")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Link: https://patch.msgid.link/20260714-scmi_core_fixes-v6-3-3afe499d46e3@kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>

0 files changed, 0 insertions, 0 deletions