rtw88: fix use after free in rtw_hw_scan_update_probe_req()

This code needs to use skb_queue_walk_safe() instead of skb_queue_walk()
because it frees the list iterator.

Fixes: d95984b5580d ("rtw88: fix memory overrun and memory leak during hw_scan")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220203082532.GA25151@kili

diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c
index ce9535c..4c8e5ea 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/fw.c
+++ b/drivers/net/wireless/realtek/rtw88/fw.c
@@ -1853,7 +1853,7 @@ static int _rtw_hw_scan_update_probe_req(struct rtw_dev *rtwdev, u8 num_probes,
        rtwdev->scan_info.probe_pg_size = page_offset;
 out:
        kfree(buf);
-       skb_queue_walk(probe_req_list, skb)
+       skb_queue_walk_safe(probe_req_list, skb, tmp)
                kfree_skb(skb);
 
        return ret;
@@ -1864,7 +1864,7 @@ static int rtw_hw_scan_update_probe_req(struct rtw_dev *rtwdev,
 {
        struct cfg80211_scan_request *req = rtwvif->scan_req;
        struct sk_buff_head list;
-       struct sk_buff *skb;
+       struct sk_buff *skb, *tmp;
        u8 num = req->n_ssids, i, bands = 0;
        int ret;
 
@@ -1889,7 +1889,7 @@ static int rtw_hw_scan_update_probe_req(struct rtw_dev *rtwdev,
        return _rtw_hw_scan_update_probe_req(rtwdev, num * bands, &list);
 
 out:
-       skb_queue_walk(&list, skb)
+       skb_queue_walk_safe(&list, skb, tmp)
                kfree_skb(skb);
 
        return ret;