From: Johannes Berg <johannes.berg@xxxxxxxxx> commit 0016d3201753b59f3ae84b868fe66c86ad256f19 upstream. The new opmode notification used this attribute with a u8, when it's documented as a u32 and indeed used in userspace as such, it just happens to work on little-endian systems since userspace isn't doing any strict size validation, and the u8 goes into the lower byte. Fix this. Cc: stable@xxxxxxxxxxxxxxx Fixes: 466b9936bf93 ("cfg80211: Add support to notify station's opmode change to userspace") Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Link: https://lore.kernel.org/r/20200325090531.be124f0a11c7.Iedbf4e197a85471ebd729b186d5365c0343bf7a8@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/wireless/nl80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -15607,7 +15607,7 @@ void cfg80211_sta_opmode_change_notify(s goto nla_put_failure; if ((sta_opmode->changed & STA_OPMODE_MAX_BW_CHANGED) && - nla_put_u8(msg, NL80211_ATTR_CHANNEL_WIDTH, sta_opmode->bw)) + nla_put_u32(msg, NL80211_ATTR_CHANNEL_WIDTH, sta_opmode->bw)) goto nla_put_failure; if ((sta_opmode->changed & STA_OPMODE_N_SS_CHANGED) &&