[ldv-project] [PATCH] rtl8187: fix use after free on failure path in rtl8187_probe()

[Alexey Khoroshilov]

If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
incorrectly and usb_dev can be used after memory deallocation.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>
---
 drivers/net/wireless/rtl818x/rtl8187/dev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
index fd78df813a85..d7f540a9dc9b 100644
--- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
@@ -1636,10 +1636,10 @@ static int rtl8187_probe(struct usb_interface *intf,
 
  err_free_dmabuf:
 	kfree(priv->io_dmabuf);
- err_free_dev:
-	ieee80211_free_hw(dev);
 	usb_set_intfdata(intf, NULL);
 	usb_put_dev(udev);
+ err_free_dev:
+	ieee80211_free_hw(dev);
 	return err;
 }
 
-- 
1.8.3.2