rtw88: check for validity before using a pointer

ieee80211_probereq_get() can return NULL. Pointer skb should be checked
for validty before use. If it is not valid, list of skbs needs to be
freed.

Fixes: 10d162b2ed39 ("rtw88: 8822c: add ieee80211_ops::hw_scan")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220121070813.9656-2-pkshih@realtek.com

diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c
index 2f7c036f90221e1bc009555cd807fcf7f43373c2..b56dc43229d2811e6efcbe85d1e3a877c4dcaeab 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/fw.c
+++ b/drivers/net/wireless/realtek/rtw88/fw.c
@@ -1866,11 +1866,19 @@ static int rtw_hw_scan_update_probe_req(struct rtw_dev *rtwdev,
                                             req->ssids[i].ssid,
                                             req->ssids[i].ssid_len,
                                             req->ie_len);
+               if (!skb)
+                       goto out;
                rtw_append_probe_req_ie(rtwdev, skb, &list, rtwvif);
                kfree_skb(skb);
        }
 
        return _rtw_hw_scan_update_probe_req(rtwdev, num, &list);
+
+out:
+       skb_queue_walk(&list, skb)
+               kfree_skb(skb);
+
+       return -ENOMEM;
 }
 
 static int rtw_add_chan_info(struct rtw_dev *rtwdev, struct rtw_chan_info *info,