[PATCH] rsi: fix use-after-free on failed probe and unbind

[Johan Hovold]

Make sure to stop both URBs before returning after failed probe as well
as on disconnect to avoid use-after-free in the completion handler.

Reported-by: syzbot+b563b7f8dbe8223a51e8@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: a4302bff28e2 ("rsi: add bluetooth rx endpoint")
Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable <stable@xxxxxxxxxxxxxxx>     # 3.15
Cc: Siva Rebbagondla <siva.rebbagondla@xxxxxxxxxxxxxxxxxx>
Cc: Prameela Rani Garnepudi <prameela.j04cs@xxxxxxxxx>
Cc: Amitkumar Karwar <amit.karwar@xxxxxxxxxxxxxxxxxx>
Cc: Fariya Fatima <fariyaf@xxxxxxxxx>

rsi: fix use-after-free on probe errors

The driver would fail to stop the command timer in most error paths,
something which specifically could lead to the timer being freed while
still active on I/O errors during probe.

Fix this by making sure that each function starting the timer also stops
it in all relevant error paths.

Reported-by: syzbot+1d1597a5aa3679c65b9f@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b78e91bcfb33 ("rsi: Add new firmware loading method")
Cc: stable <stable@xxxxxxxxxxxxxxx>     # 4.12
Cc: Prameela Rani Garnepudi <prameela.j04cs@xxxxxxxxx>
Cc: Amitkumar Karwar <amit.karwar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
 drivers/net/wireless/rsi/rsi_91x_hal.c | 12 ++++++------
 drivers/net/wireless/rsi/rsi_91x_usb.c | 18 +++++++++++++++++-
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_hal.c b/drivers/net/wireless/rsi/rsi_91x_hal.c
index f84250bdb8cf..6f8d5f9a9f7e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_hal.c
+++ b/drivers/net/wireless/rsi/rsi_91x_hal.c
@@ -622,6 +622,7 @@ static int bl_cmd(struct rsi_hw *adapter, u8 cmd, u8 exp_resp, char *str)
 	bl_start_cmd_timer(adapter, timeout);
 	status = bl_write_cmd(adapter, cmd, exp_resp, &regout_val);
 	if (status < 0) {
+		bl_stop_cmd_timer(adapter);
 		rsi_dbg(ERR_ZONE,
 			"%s: Command %s (%0x) writing failed..\n",
 			__func__, str, cmd);
@@ -737,10 +738,9 @@ static int ping_pong_write(struct rsi_hw *adapter, u8 cmd, u8 *addr, u32 size)
 	}
 
 	status = bl_cmd(adapter, cmd_req, cmd_resp, str);
-	if (status) {
-		bl_stop_cmd_timer(adapter);
+	if (status)
 		return status;
-	}
+
 	return 0;
 }
 
@@ -828,10 +828,9 @@ static int auto_fw_upgrade(struct rsi_hw *adapter, u8 *flash_content,
 
 	status = bl_cmd(adapter, EOF_REACHED, FW_LOADING_SUCCESSFUL,
 			"EOF_REACHED");
-	if (status) {
-		bl_stop_cmd_timer(adapter);
+	if (status)
 		return status;
-	}
+
 	rsi_dbg(INFO_ZONE, "FW loading is done and FW is running..\n");
 	return 0;
 }
@@ -849,6 +848,7 @@ static int rsi_hal_prepare_fwload(struct rsi_hw *adapter)
 						  &regout_val,
 						  RSI_COMMON_REG_SIZE);
 		if (status < 0) {
+			bl_stop_cmd_timer(adapter);
 			rsi_dbg(ERR_ZONE,
 				"%s: REGOUT read failed\n", __func__);
 			return status;
diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 53f41fc2cadf..30bed719486e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -292,6 +292,15 @@ static void rsi_rx_done_handler(struct urb *urb)
 		dev_kfree_skb(rx_cb->rx_skb);
 }
 
+static void rsi_rx_urb_kill(struct rsi_hw *adapter, u8 ep_num)
+{
+	struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
+	struct rx_usb_ctrl_block *rx_cb = &dev->rx_cb[ep_num - 1];
+	struct urb *urb = rx_cb->rx_urb;
+
+	usb_kill_urb(urb);
+}
+
 /**
  * rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
  * @adapter: Pointer to the adapter structure.
@@ -823,10 +832,13 @@ static int rsi_probe(struct usb_interface *pfunction,
 	if (adapter->priv->coex_mode > 1) {
 		status = rsi_rx_urb_submit(adapter, BT_EP);
 		if (status)
-			goto err1;
+			goto err_kill_wlan_urb;
 	}
 
 	return 0;
+
+err_kill_wlan_urb:
+	rsi_rx_urb_kill(adapter, WLAN_EP);
 err1:
 	rsi_deinit_usb_interface(adapter);
 err:
@@ -857,6 +869,10 @@ static void rsi_disconnect(struct usb_interface *pfunction)
 		adapter->priv->bt_adapter = NULL;
 	}
 
+	if (adapter->priv->coex_mode > 1)
+		rsi_rx_urb_kill(adapter, BT_EP);
+	rsi_rx_urb_kill(adapter, WLAN_EP);
+
 	rsi_reset_card(adapter);
 	rsi_deinit_usb_interface(adapter);
 	rsi_91x_deinit(adapter);
-- 
2.24.0