From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit beb12813bc75d4a23de43b85ad1c7cb28d27631e ]
Seven years ago we tried to fix a leak but actually introduced a double free instead. It was an understandable mistake because the code was a bit confusing and the free was done in the wrong place. The "skb" pointer is freed in both _rtl_usb_tx_urb_setup() and _rtl_usb_transmit(). The free belongs _rtl_usb_transmit() instead of _rtl_usb_tx_urb_setup() and I've cleaned the code up a bit to hopefully make it more clear.
Fixes: 36ef0b473fbf ("rtlwifi: usb: add missing freeing of skbuff") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20200513093951.GD347693@mwanda Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/realtek/rtlwifi/usb.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c index 348b0072cdd6..c66c6dc00378 100644 --- a/drivers/net/wireless/realtek/rtlwifi/usb.c +++ b/drivers/net/wireless/realtek/rtlwifi/usb.c @@ -881,10 +881,8 @@ static struct urb *_rtl_usb_tx_urb_setup(struct ieee80211_hw *hw,
WARN_ON(NULL == skb); _urb = usb_alloc_urb(0, GFP_ATOMIC); - if (!_urb) { - kfree_skb(skb); + if (!_urb) return NULL; - } _rtl_install_trx_info(rtlusb, skb, ep_num); usb_fill_bulk_urb(_urb, rtlusb->udev, usb_sndbulkpipe(rtlusb->udev, ep_num), skb->data, skb->len, _rtl_tx_complete, skb); @@ -898,7 +896,6 @@ static void _rtl_usb_transmit(struct ieee80211_hw *hw, struct sk_buff *skb, struct rtl_usb *rtlusb = rtl_usbdev(rtl_usbpriv(hw)); u32 ep_num; struct urb *_urb = NULL; - struct sk_buff *_skb = NULL;
WARN_ON(NULL == rtlusb->usb_tx_aggregate_hdl); if (unlikely(IS_USB_STOP(rtlusb))) { @@ -907,8 +904,7 @@ static void _rtl_usb_transmit(struct ieee80211_hw *hw, struct sk_buff *skb, return; } ep_num = rtlusb->ep_map.ep_mapping[qnum]; - _skb = skb; - _urb = _rtl_usb_tx_urb_setup(hw, _skb, ep_num); + _urb = _rtl_usb_tx_urb_setup(hw, skb, ep_num); if (unlikely(!_urb)) { pr_err("Can't allocate urb. Drop skb!\n"); kfree_skb(skb);