From: Ming Lei <ming.lei@canonical.com>
Date: Thu, 13 Sep 2012 02:33:28 +0000 (+0800)
Subject: wireless: ath9k-htc: fix possible use after free
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e962610f8100e1b52973f5a9c855cbc3d1ba04ec;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

wireless: ath9k-htc: fix possible use after free

Inside ath9k_hif_usb_firmware_fail(), the instance of
'struct struct hif_device_usb' may be freed by
ath9k_hif_usb_disconnect() after

	complete(&hif_dev->fw_done);

But 'hif_dev' is still accessed after the line code
above is executed.

This patch fixes the issue by not accessing 'hif_dev'
after 'complete(&hif_dev->fw_done)' inside
ath9k_hif_usb_firmware_fail().

Cc: ath9k-devel@lists.ath9k.org
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Cc: Jouni Malinen <jouni@qca.qualcomm.com>
Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index ee6e50aebf8d..924c4616c3d9 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -1072,14 +1072,15 @@ static void ath9k_hif_usb_dev_deinit(struct hif_device_usb *hif_dev)
  */
 static void ath9k_hif_usb_firmware_fail(struct hif_device_usb *hif_dev)
 {
-	struct device *parent = hif_dev->udev->dev.parent;
+	struct device *dev = &hif_dev->udev->dev;
+	struct device *parent = dev->parent;
 
 	complete(&hif_dev->fw_done);
 
 	if (parent)
 		device_lock(parent);
 
-	device_release_driver(&hif_dev->udev->dev);
+	device_release_driver(dev);
 
 	if (parent)
 		device_unlock(parent);