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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jimmy Assarsson <extja@kvaser.com>,
        Anssi Hannula <anssi.hannula@bitwise.fi>,
        Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 5.15 022/530] can: kvaser_usb: Fix use of uninitialized completion
Date:   Mon, 24 Oct 2022 13:26:06 +0200
Message-Id: <20221024113046.016827466@linuxfoundation.org>
In-Reply-To: <20221024113044.976326639@linuxfoundation.org>
References: <20221024113044.976326639@linuxfoundation.org>
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From: Anssi Hannula <anssi.hannula@bitwise.fi>

commit cd7f30e174d09a02ca2afa5ef093fb0f0352e0d8 upstream.

flush_comp is initialized when CMD_FLUSH_QUEUE is sent to the device and
completed when the device sends CMD_FLUSH_QUEUE_RESP.

This causes completion of uninitialized completion if the device sends
CMD_FLUSH_QUEUE_RESP before CMD_FLUSH_QUEUE is ever sent (e.g. as a
response to a flush by a previously bound driver, or a misbehaving
device).

Fix that by initializing flush_comp in kvaser_usb_init_one() like the
other completions.

This issue is only triggerable after RX URBs have been set up, i.e. the
interface has been opened at least once.

Cc: stable@vger.kernel.org
Fixes: aec5fb2268b7 ("can: kvaser_usb: Add support for Kvaser USB hydra family")
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/20221010150829.199676-3-extja@kvaser.com
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_core.c  |    1 +
 drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c |    2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -717,6 +717,7 @@ static int kvaser_usb_init_one(struct kv
 	init_usb_anchor(&priv->tx_submitted);
 	init_completion(&priv->start_comp);
 	init_completion(&priv->stop_comp);
+	init_completion(&priv->flush_comp);
 	priv->can.ctrlmode_supported = 0;
 
 	priv->dev = dev;
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -1914,7 +1914,7 @@ static int kvaser_usb_hydra_flush_queue(
 {
 	int err;
 
-	init_completion(&priv->flush_comp);
+	reinit_completion(&priv->flush_comp);
 
 	err = kvaser_usb_hydra_send_simple_cmd(priv->dev, CMD_FLUSH_QUEUE,
 					       priv->channel);