From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Nguyen Dinh Phi <phind.uet@gmail.com>,
        syzbot+bbf402b783eeb6d908db@syzkaller.appspotmail.com,
        Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH 4.4 146/162] cfg80211: call cfg80211_stop_ap when switch from P2P_GO type
Date:   Wed, 24 Nov 2021 12:57:29 +0100
Message-Id: <20211124115703.000074135@linuxfoundation.org>
In-Reply-To: <20211124115658.328640564@linuxfoundation.org>
References: <20211124115658.328640564@linuxfoundation.org>
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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
@@ -963,6 +963,7 @@ 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: