[PATCH] staging: wlan-ng: fix use-after-free Read in hfa384x_usbin_callback

[Qiujun Huang]

We can't handle the case length > WLAN_DATA_MAXLEN.
Because the size of rxfrm->data is WLAN_DATA_MAXLEN(2312), and we can't
read more than that.

Thanks-to: Hillf Danton <hdanton at sina.com>
Reported-and-tested-by: syzbot+7d42d68643a35f71ac8a at syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain at gmail.com>
---
 drivers/staging/wlan-ng/hfa384x_usb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/wlan-ng/hfa384x_usb.c b/drivers/staging/wlan-ng/hfa384x_usb.c
index b71756ab0394..7fe64fcd385d 100644
--- a/drivers/staging/wlan-ng/hfa384x_usb.c
+++ b/drivers/staging/wlan-ng/hfa384x_usb.c
@@ -3372,6 +3372,8 @@ static void hfa384x_int_rxmonitor(struct wlandevice *wlandev,
 	     WLAN_HDR_A4_LEN + WLAN_DATA_MAXLEN + WLAN_CRC_LEN)) {
 		pr_debug("overlen frm: len=%zd\n",
 			 skblen - sizeof(struct p80211_caphdr));
+
+		return;
 	}
 
 	skb = dev_alloc_skb(skblen);
-- 
2.17.1