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From:   Qiujun Huang <hqjagain@gmail.com>
To:     gregkh@linuxfoundation.org, osdevtc@gmail.com
Cc:     devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
        anenbupt@gmail.com, hdanton@sina.com,
        Qiujun Huang <hqjagain@gmail.com>
Subject: [PATCH] staging: wlan-ng: fix use-after-free Read in hfa384x_usbin_callback
Date:   Thu, 26 Mar 2020 21:18:50 +0800
Message-Id: <20200326131850.17711-1-hqjagain@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@sina.com>
Reported-and-tested-by: syzbot+7d42d68643a35f71ac8a@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@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