wifi: nl80211: strict checking attributes for NL80211_CMD_SET_BSS

Assure user-space only modifies attributes for NL80211_CMD_SET_BSS
that are supported by the driver. This stricter checking is only done
when user-space commits to it by including NL80211_ATTR_BSS_PARAM.

Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Link: https://patch.msgid.link/20250817190435.1495094-4-arend.vanspriel@broadcom.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 45 insertions, 7 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 153644a04072..99e2aadc65f7 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -879,6 +879,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_S1G_LONG_BEACON_PERIOD] = NLA_POLICY_MIN(NLA_U8, 2),
 	[NL80211_ATTR_S1G_SHORT_BEACON] =
 		NLA_POLICY_NESTED(nl80211_s1g_short_beacon),
+	[NL80211_ATTR_BSS_PARAM] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -9083,6 +9084,8 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 	struct net_device *dev = info->user_ptr[1];
 	struct bss_parameters params;
 	u32 bss_param_support = rdev->wiphy.bss_param_support;
+	u32 changed = 0;
+	bool strict;
 
 	memset(&params, 0, sizeof(params));
 	params.link_id = nl80211_link_id_or_invalid(info->attrs);
@@ -9095,26 +9098,54 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 	params.p2p_ctwindow = -1;
 	params.p2p_opp_ps = -1;
 
-	if (info->attrs[NL80211_ATTR_BSS_CTS_PROT])
+	strict = nla_get_flag(info->attrs[NL80211_ATTR_BSS_PARAM]);
+	if (info->attrs[NL80211_ATTR_BSS_CTS_PROT]) {
+		if (strict && !(bss_param_support & WIPHY_BSS_PARAM_CTS_PROT))
+			return -EINVAL;
 		params.use_cts_prot =
 		    nla_get_u8(info->attrs[NL80211_ATTR_BSS_CTS_PROT]);
-	if (info->attrs[NL80211_ATTR_BSS_SHORT_PREAMBLE])
+		changed |= WIPHY_BSS_PARAM_CTS_PROT;
+	}
+	if (info->attrs[NL80211_ATTR_BSS_SHORT_PREAMBLE]) {
+		if (strict &&
+		    !(bss_param_support & WIPHY_BSS_PARAM_SHORT_PREAMBLE))
+			return -EINVAL;
 		params.use_short_preamble =
 		    nla_get_u8(info->attrs[NL80211_ATTR_BSS_SHORT_PREAMBLE]);
-	if (info->attrs[NL80211_ATTR_BSS_SHORT_SLOT_TIME])
+		changed |= WIPHY_BSS_PARAM_SHORT_PREAMBLE;
+	}
+	if (info->attrs[NL80211_ATTR_BSS_SHORT_SLOT_TIME]) {
+		if (strict &&
+		    !(bss_param_support & WIPHY_BSS_PARAM_SHORT_SLOT_TIME))
+			return -EINVAL;
 		params.use_short_slot_time =
 		    nla_get_u8(info->attrs[NL80211_ATTR_BSS_SHORT_SLOT_TIME]);
+		changed |= WIPHY_BSS_PARAM_SHORT_SLOT_TIME;
+	}
 	if (info->attrs[NL80211_ATTR_BSS_BASIC_RATES]) {
+		if (strict &&
+		    !(bss_param_support & WIPHY_BSS_PARAM_BASIC_RATES))
+			return -EINVAL;
 		params.basic_rates =
 			nla_data(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
 		params.basic_rates_len =
 			nla_len(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
+		changed |= WIPHY_BSS_PARAM_BASIC_RATES;
 	}
-	if (info->attrs[NL80211_ATTR_AP_ISOLATE])
-		params.ap_isolate = !!nla_get_u8(info->attrs[NL80211_ATTR_AP_ISOLATE]);
-	if (info->attrs[NL80211_ATTR_BSS_HT_OPMODE])
+	if (info->attrs[NL80211_ATTR_AP_ISOLATE]) {
+		if (strict && !(bss_param_support & WIPHY_BSS_PARAM_AP_ISOLATE))
+			return -EINVAL;
+		params.ap_isolate =
+			!!nla_get_u8(info->attrs[NL80211_ATTR_AP_ISOLATE]);
+		changed |= WIPHY_BSS_PARAM_AP_ISOLATE;
+	}
+	if (info->attrs[NL80211_ATTR_BSS_HT_OPMODE]) {
+		if (strict && !(bss_param_support & WIPHY_BSS_PARAM_HT_OPMODE))
+			return -EINVAL;
 		params.ht_opmode =
 			nla_get_u16(info->attrs[NL80211_ATTR_BSS_HT_OPMODE]);
+		changed |= WIPHY_BSS_PARAM_HT_OPMODE;
+	}
 
 	if (info->attrs[NL80211_ATTR_P2P_CTWINDOW]) {
 		if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
@@ -9124,6 +9155,7 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 		if (params.p2p_ctwindow != 0 &&
 		    !(bss_param_support & WIPHY_BSS_PARAM_P2P_CTWINDOW))
 			return -EINVAL;
+		changed |= WIPHY_BSS_PARAM_P2P_CTWINDOW;
 	}
 
 	if (info->attrs[NL80211_ATTR_P2P_OPPPS]) {
@@ -9132,9 +9164,11 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 		if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 			return -EINVAL;
 		tmp = nla_get_u8(info->attrs[NL80211_ATTR_P2P_OPPPS]);
+		if (tmp && !(bss_param_support & WIPHY_BSS_PARAM_P2P_OPPPS))
+			return -EINVAL;
 		params.p2p_opp_ps = tmp;
 		if (params.p2p_opp_ps &&
-		    !(bss_param_support & WIPHY_BSS_PARAM_P2P_OPPPS))
+		    !(rdev->wiphy.bss_param_support & WIPHY_BSS_PARAM_P2P_OPPPS))
 			return -EINVAL;
 	}
 
@@ -9145,6 +9179,10 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
+	changed &= rdev->wiphy.bss_param_support;
+	if (!changed)
+		return 0;
+
 	return rdev_change_bss(rdev, dev, &params);
 }