[PATCH v3] 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 <redacted>

---
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

-----Original Message-----
From: Muhammad Usama Anjum <redacted>
Sent: Friday, December 24, 2021 4:55 PM
To: Yan-Hsuan Chuang <redacted>; Kalle Valo <kvalo@kernel.org>; David S. Miller
[off-list ref]; Jakub Kicinski [off-list ref]; Pkshih [off-list ref]; Bernie Huang
[off-list ref]; open list:REALTEK WIRELESS DRIVER (rtw88) [off-list ref]; open
list:NETWORKING DRIVERS [off-list ref]; open list [off-list ref]
Cc: usama.anjum@collabora.com; kernel@collabora.com
Subject: [PATCH v3] 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 <redacted>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

[...]

-----Original Message-----
From: Pkshih <pkshih@realtek.com>
Sent: Friday, December 24, 2021 5:01 PM
To: Muhammad Usama Anjum <redacted>; Yan-Hsuan Chuang <redacted>; Kalle
Valo [off-list ref]; David S. Miller [off-list ref]; Jakub Kicinski [off-list ref]; Bernie
Huang [off-list ref]; open list:REALTEK WIRELESS DRIVER (rtw88) [off-list ref];
open list:NETWORKING DRIVERS [off-list ref]; open list [off-list ref]
Cc: kernel@collabora.com
Subject: RE: [PATCH v3] rtw88: check for validity before using a pointer

quoted

-----Original Message-----
From: Muhammad Usama Anjum <redacted>
Sent: Friday, December 24, 2021 4:55 PM
To: Yan-Hsuan Chuang <redacted>; Kalle Valo <kvalo@kernel.org>; David S. Miller
[off-list ref]; Jakub Kicinski [off-list ref]; Pkshih [off-list ref]; Bernie Huang
[off-list ref]; open list:REALTEK WIRELESS DRIVER (rtw88) [off-list ref]; open
list:NETWORKING DRIVERS [off-list ref]; open list [off-list ref]
Cc: usama.anjum@collabora.com; kernel@collabora.com
Subject: [PATCH v3] 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 <redacted>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

[...]

I take this patch into my patchset [1], because my new patches are based this patch
related to fixes of hw_scan.

[1] https://lore.kernel.org/linux-wireless/20220121070813.9656-2-pkshih@realtek.com/T/#u

--
Ping-Ke