[PATCH 5.4 097/155] nl80211: fix NL80211_ATTR_CHANNEL_WIDTH attribute type

Greg Kroah-Hartman
2020-03-31T09:15:52Z

From: Johannes Berg <johannes.berg@intel.com>

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@vger.kernel.org
Fixes: 466b9936bf93 ("cfg80211: Add support to notify station's opmode change to userspace")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200325090531.be124f0a11c7.Iedbf4e197a85471ebd729b186d5365c0343bf7a8@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/wireless/nl80211.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -16407,7 +16407,7 @@ 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) &&