[PATCH 4.9 195/207] cfg80211: call cfg80211_stop_ap when switch from P2P_GO type

Greg Kroah-Hartman
2021-11-24T12:29:42Z

From: Nguyen Dinh Phi <phind.uet@gmail.com>

commit 563fbefed46ae4c1f70cffb8eb54c02df480b2c2 upstream.

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: ac800140c20e ("cfg80211: .stop_ap when interface is going down")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/wireless/util.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1035,6 +1035,7 @@ int cfg80211_change_iface(struct cfg8021

switch (otype) {
case NL80211_IFTYPE_AP:
+ case NL80211_IFTYPE_P2P_GO:
cfg80211_stop_ap(rdev, dev, true);
break;
case NL80211_IFTYPE_ADHOC: