From 4893deede7bbcad5189ec8bb0554cc9ceecf6d85 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz Date: Fri, 12 Jun 2026 10:21:09 -0400 Subject: [PATCH] Bluetooth: 6lowpan: Fix using chan->conn as indication to no remote netdev commit d38eaf611839b85ade3dd3db309dbc8aaaaf0095 upstream. b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") don't reset the chan->conn to NULL anymore making the bt# netdev not be remove once the last l2cap_chan_del is removed. Instead of restoring the original behavior this remove the logic of keeping the interface after the last channel is removed because it never worked as intended and the l2cap_chan_del always detach its l2cap_conn which results in always removing the channel anyway. Fixes: b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/6lowpan.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index 172b0bb7127a..8625d3db2442 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -781,20 +781,10 @@ static void chan_close_cb(struct l2cap_chan *chan) struct lowpan_btle_dev *dev = NULL; struct lowpan_peer *peer; int err = -ENOENT; - bool last = false, remove = true; + bool last = false; BT_DBG("chan %p conn %p", chan, chan->conn); - if (chan->conn && chan->conn->hcon) { - if (!is_bt_6lowpan(chan->conn->hcon)) - return; - - /* If conn is set, then the netdev is also there and we should - * not remove it. - */ - remove = false; - } - spin_lock(&devices_lock); list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { @@ -821,10 +811,8 @@ static void chan_close_cb(struct l2cap_chan *chan) ifdown(dev->netdev); - if (remove) { - INIT_WORK(&entry->delete_netdev, delete_netdev); - schedule_work(&entry->delete_netdev); - } + INIT_WORK(&entry->delete_netdev, delete_netdev); + schedule_work(&entry->delete_netdev); } else { spin_unlock(&devices_lock); }