[PATCH] net:wireless: call cfg80211_stop_ap when switch from P2P_GO type

From: Nguyen Dinh Phi
Date: Wed Oct 27 2021 - 13:29:46 EST


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@xxxxxxxxx>
Reported-by: syzbot+bbf402b783eeb6d908db@xxxxxxxxxxxxxxxxxxxxxxxxx
---
net/wireless/util.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 18dba3d7c638..4fdf0877092d 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1044,6 +1044,7 @@ 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:
--
2.25.1