nl80211: validate S1G channel width

Validate the S1G channel width input by user to ensure it matches
that of the requested channel

Signed-off-by: Kieran Frewen <[e-mail]>
Signed-off-by: Bassem Dawood <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Johannes Berg <[e-mail]>

net/wireless/nl80211.c

···
 	} else if (attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
 		chandef->width =
 			nla_get_u32(attrs[NL80211_ATTR_CHANNEL_WIDTH]);
+		if (chandef->chan->band == NL80211_BAND_S1GHZ) {
+			/* User input error for channel width doesn't match channel  */
+			if (chandef->width != ieee80211_s1g_channel_width(chandef->chan)) {
+				NL_SET_ERR_MSG_ATTR(extack,
+						    attrs[NL80211_ATTR_CHANNEL_WIDTH],
+						    "bad channel width");
+				return -EINVAL;
+			}
+		}
 		if (attrs[NL80211_ATTR_CENTER_FREQ1]) {
 			chandef->center_freq1 =
 				nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ1]);