cfg80211: call cfg80211_stop_ap when switch from P2P_GO type

If the userspace tools switch from NL80211_IFTYPE_P2P_GO to
NL80211_IFTYPE_ADHOC via send_msg(NL80211_CMD_SET_INTERFACE), it
does not call the cleanup cfg80211_stop_ap(), this leads to the
initialization of in-use data. For example, this path re-init the
sdata->assigned_chanctx_list while it is still an element of
assigned_vifs list, and makes that linked list corrupt.

Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Reported-by: syzbot+bbf402b783eeb6d908db@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20211027173722.777287-1-phind.uet@gmail.com
Cc: stable@vger.kernel.org
Fixes: 835bb92a5e94 ("cfg80211: .stop_ap when interface is going down")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 5ff1f8726faf8d944ba24968e6dc9eaca5f38a0f..41ea65deb6e1f1b653b0c18d3af86fc1b62c2680 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1046,6 +1046,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 
                switch (otype) {
                case NL80211_IFTYPE_AP:
+               case NL80211_IFTYPE_P2P_GO:
                        cfg80211_stop_ap(rdev, dev, true);
                        break;
                case NL80211_IFTYPE_ADHOC: