From 563fbefed46ae4c1f70cffb8eb54c02df480b2c2 Mon Sep 17 00:00:00 2001
From: Nguyen Dinh Phi <phind.uet@gmail.com>
Date: Thu, 28 Oct 2021 01:37:22 +0800
Subject: [PATCH] cfg80211: call cfg80211_stop_ap when switch from P2P_GO type
Git-commit: 563fbefed46ae4c1f70cffb8eb54c02df480b2c2
Patch-mainline: v5.16-rc2
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/wireless/util.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 5ff1f8726faf..41ea65deb6e1 100644
--- 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:
-- 
2.26.2