[PATCH 4.14 048/209] rtl818x: fix potential use after free

Greg Kroah-Hartman
2019-12-04T18:23:37Z

From: Pan Bian <bianpan2016@163.com>

[ Upstream commit afbb1947db94eacc5a13302eee88a9772fb78935 ]

entry is released via usb_put_urb just after calling usb_submit_urb.
However, entry is used if the submission fails, resulting in a use after
free bug. The patch fixes this.

Signed-off-by: Pan Bian <bianpan2016@163.com>
ACKed-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
index 9a1d15b3ce453..518caaaf8a987 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
@@ -444,12 +444,13 @@ static int rtl8187_init_urbs(struct ieee80211_hw *dev)
skb_queue_tail(&priv->rx_queue, skb);
usb_anchor_urb(entry, &priv->anchored);
ret = usb_submit_urb(entry, GFP_KERNEL);
- usb_put_urb(entry);
if (ret) {
skb_unlink(skb, &priv->rx_queue);
usb_unanchor_urb(entry);
+ usb_put_urb(entry);
goto err;
}
+ usb_put_urb(entry);
}
return ret;

--
2.20.1