s390/qeth: fix qdio teardown after early init error

qeth_l?_set_online() goes through a number of initialization steps, and
on any error uses qeth_l?_stop_card() to tear down the residual state.

The first initialization step is qeth_core_hardsetup_card(). When this
fails after having established a QDIO context on the device
(ie. somewhere after qeth_mpc_initialize()), qeth_l?_stop_card() doesn't
shut down this QDIO context again (since the card state hasn't
progressed from DOWN at this stage).

Even worse, we then call qdio_free() as final teardown step to free the
QDIO data structures - while some of them are still hooked into wider
QDIO infrastructure such as the IRQ list. This is inevitably followed by
use-after-frees and other nastyness.

Fix this by unconditionally calling qeth_qdio_clear_card() to shut down
the QDIO context, and also to halt/clear any pending activity on the
various IO channels.
Remove the naive attempt at handling the teardown in
qeth_mpc_initialize(), it clearly doesn't suffice and we're handling it
properly now in the wider teardown code.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 04e301de376f..5508ab89b518 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1307,12 +1307,12 @@ static void qeth_l3_stop_card(struct qeth_card *card)
 		card->state = CARD_STATE_HARDSETUP;
 	}
 	if (card->state == CARD_STATE_HARDSETUP) {
-		qeth_qdio_clear_card(card, 0);
 		qeth_drain_output_queues(card);
 		qeth_clear_working_pool_list(card);
 		card->state = CARD_STATE_DOWN;
 	}
 
+	qeth_qdio_clear_card(card, 0);
 	flush_workqueue(card->event_wq);
 	card->info.promisc_mode = 0;
 }