[PATCH] wifi: rtw88: allow key removal when the CAM table is full

[Hungyu Lin]

rtw_ops_set_key() looks for a free CAM entry before checking the
command. When all pairwise entries are in use, DISABLE_KEY returns
-ENOSPC without clearing the existing entry.

Move the allocation and bounds check into SET_KEY. DISABLE_KEY uses
the existing key->hw_key_idx.

Fixes: 10d58823cb44 ("wifi: rtw88: fix out-of-bounds CAM write when key table is full")
Signed-off-by: Hungyu Lin <dennylin0707@xxxxxxxxx>
---
 drivers/net/wireless/realtek/rtw88/mac80211.c | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
index 2a9b09fa76e7..5e40cf06a9e3 100644
--- a/drivers/net/wireless/realtek/rtw88/mac80211.c
+++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
@@ -598,20 +598,20 @@ static int rtw_ops_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 
 	rtw_leave_lps_deep(rtwdev);
 
-	if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE) {
-		hw_key_idx = rtw_sec_get_free_cam(sec);
-	} else {
-		/* multiple interfaces? */
-		hw_key_idx = key->keyidx;
-	}
-
-	if (hw_key_idx >= sec->total_cam_num) {
-		ret = -ENOSPC;
-		goto out;
-	}
-
 	switch (cmd) {
 	case SET_KEY:
+		if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE) {
+			hw_key_idx = rtw_sec_get_free_cam(sec);
+		} else {
+			/* multiple interfaces? */
+			hw_key_idx = key->keyidx;
+		}
+
+		if (hw_key_idx >= sec->total_cam_num) {
+			ret = -ENOSPC;
+			goto out;
+		}
+
 		/* need sw generated IV */
 		key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
 		key->hw_key_idx = hw_key_idx;