[PATCH v3] rtw88: check for validity before using a pointer

* [PATCH v3] rtw88: check for validity before using a pointer
@ 2021-12-24  8:54 Muhammad Usama Anjum
  2021-12-24  9:00 ` Pkshih
  0 siblings, 1 reply; 3+ messages in thread
From: Muhammad Usama Anjum @ 2021-12-24  8:54 UTC (permalink / raw)
  To: Yan-Hsuan Chuang, Kalle Valo, David S. Miller, Jakub Kicinski,
	Ping-Ke Shih, Po-Hao Huang,
	open list:REALTEK WIRELESS DRIVER (rtw88),
	open list:NETWORKING DRIVERS, open list
  Cc: usama.anjum, kernel

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>

---
v3:
Use skb_queue_walk instead of skb_queue_walk_safe
v2:
Free the list in case of error
---
 drivers/net/wireless/realtek/rtw88/fw.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c
index 2f7c036f9022..b56dc43229d2 100644
--- 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,
-- 
2.30.2


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