[PATCH RESEND] iwlegacy: Adjust input parameter validation in il_set_ht_add_station()

[Markus Elfring]

From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 19 Apr 2023 18:35:55 +0200

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “il_set_ht_add_station”.

Thus avoid the risk for undefined behaviour by moving the assignment
for the variable “sta_ht_inf” behind the null pointer check.

This issue was detected by using the Coccinelle software.


Delete also the jump target “done” by using return statements directly
for two if branches.

Fixes: 046d2e7c50e3 ("mac80211: prepare sta handling for MLO support")
Fixes: e7392364fcd1 ("iwlegacy: indentions and whitespaces")
Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/net/wireless/intel/iwlegacy/common.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
index 96002121bb8b..8f6fd17b02a8 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.c
+++ b/drivers/net/wireless/intel/iwlegacy/common.c
@@ -1863,11 +1863,15 @@ EXPORT_SYMBOL(il_send_add_sta);
 static void
 il_set_ht_add_station(struct il_priv *il, u8 idx, struct ieee80211_sta *sta)
 {
-	struct ieee80211_sta_ht_cap *sta_ht_inf = &sta->deflink.ht_cap;
+	struct ieee80211_sta_ht_cap *sta_ht_inf;
 	__le32 sta_flags;

-	if (!sta || !sta_ht_inf->ht_supported)
-		goto done;
+	if (!sta)
+		return;
+
+	sta_ht_inf = &sta->deflink.ht_cap;
+	if (!sta_ht_inf->ht_supported)
+		return;

 	D_ASSOC("spatial multiplexing power save mode: %s\n",
 		(sta->deflink.smps_mode == IEEE80211_SMPS_STATIC) ? "static" :
@@ -1906,8 +1910,6 @@ il_set_ht_add_station(struct il_priv *il, u8 idx, struct ieee80211_sta *sta)
 		sta_flags &= ~STA_FLG_HT40_EN_MSK;

 	il->stations[idx].sta.station_flags = sta_flags;
-done:
-	return;
 }

 /*
--
2.40.0