From: Anssi Hannula anssi.hannula@bitwise.fi

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.

Cc: stable@vger.kernel.org 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/20220903182559.189-3-extja@kvaser.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- 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 3dcd35979e6f..3abfaa77e893 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c @@ -1875,7 +1875,7 @@ 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); @@ -1893,7 +1893,7 @@ 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 8e11cda85624..9683bc5e8257 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c @@ -1320,7 +1320,7 @@ 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); @@ -1338,7 +1338,7 @@ 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);