From 33ddee2b95abecfb503639e1028b70df09f4cb23 Mon Sep 17 00:00:00 2001
From: Anssi Hannula <anssi.hannula@bitwise.fi>
Date: Mon, 10 Oct 2022 20:52:27 +0200
Subject: [PATCH] can: kvaser_usb: Fix possible completions during
init_completion
commit 2871edb32f4622c3a25ce4b3977bad9050b91974 upstream.
kvaser_usb uses completions to signal when a response event is received
for outgoing commands.
However, it uses init_completion() to reinitialize the start_comp and
stop_comp completions before sending the start/stop commands.
In case the device sends the corresponding response just before the
actual command is sent, complete() may be called concurrently with
init_completion() which is not safe.
This might be triggerable even with a properly functioning device by
stopping the interface (CMD_STOP_CHIP) just after it goes bus-off (which
also causes the driver to send CMD_STOP_CHIP when restart-ms is off),
but that was not tested.
Fix the issue by using reinit_completion() instead.
Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
Tested-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/all/20221010185237.319219-2-extja@kvaser.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 4 ++--
drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
index 45eb7e462ce9..3ff2cd9828d2 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -1873,7 +1873,7 @@ static int kvaser_usb_hydra_start_chip(struct kvaser_usb_net_priv *priv)
{
int err;
- init_completion(&priv->start_comp);
+ reinit_completion(&priv->start_comp);
err = kvaser_usb_hydra_send_simple_cmd(priv->dev, CMD_START_CHIP_REQ,
priv->channel);
@@ -1891,7 +1891,7 @@ static int kvaser_usb_hydra_stop_chip(struct kvaser_usb_net_priv *priv)
{
int err;
- init_completion(&priv->stop_comp);
+ reinit_completion(&priv->stop_comp);
/* Make sure we do not report invalid BUS_OFF from CMD_CHIP_STATE_EVENT
* see comment in kvaser_usb_hydra_update_state()
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index 4312be05fc5b..7a71097281c2 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -1324,7 +1324,7 @@ static int kvaser_usb_leaf_start_chip(struct kvaser_usb_net_priv *priv)
{
int err;
- init_completion(&priv->start_comp);
+ reinit_completion(&priv->start_comp);
err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_START_CHIP,
priv->channel);
@@ -1342,7 +1342,7 @@ static int kvaser_usb_leaf_stop_chip(struct kvaser_usb_net_priv *priv)
{
int err;
- init_completion(&priv->stop_comp);
+ reinit_completion(&priv->stop_comp);
err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_STOP_CHIP,
priv->channel);