6.6-stable review patch. If anyone has any objections, please let me know.
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From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
[ Upstream commit 581dd2dc168fe0ed2a7a5534a724f0d3751c93ae ]
The usage of rcu_read_(un)lock while inside list_for_each_entry_rcu is not safe since for the most part entries fetched this way shall be treated as rcu_dereference:
Note that the value returned by rcu_dereference() is valid only within the enclosing RCU read-side critical section [1]_. For example, the following is **not** legal::
rcu_read_lock(); p = rcu_dereference(head.next); rcu_read_unlock(); x = p->address; /* BUG!!! */ rcu_read_lock(); y = p->data; /* BUG!!! */ rcu_read_unlock();
Fixes: a0bfde167b50 ("Bluetooth: ISO: Add support for connecting multiple BISes") Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/hci_event.c | 33 +++++++++++---------------------- 1 file changed, 11 insertions(+), 22 deletions(-)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 141b4fce55e3..01e51e1dc9b3 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -6821,38 +6821,27 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data, return;
hci_dev_lock(hdev); - rcu_read_lock();
/* Connect all BISes that are bound to the BIG */ - list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) { - if (bacmp(&conn->dst, BDADDR_ANY) || - conn->type != ISO_LINK || - conn->iso_qos.bcast.big != ev->handle) + while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle, + BT_BOUND))) { + if (ev->status) { + hci_connect_cfm(conn, ev->status); + hci_conn_del(conn); continue; + }
if (hci_conn_set_handle(conn, __le16_to_cpu(ev->bis_handle[i++]))) continue;
- if (!ev->status) { - conn->state = BT_CONNECTED; - set_bit(HCI_CONN_BIG_CREATED, &conn->flags); - rcu_read_unlock(); - hci_debugfs_create_conn(conn); - hci_conn_add_sysfs(conn); - hci_iso_setup_path(conn); - rcu_read_lock(); - continue; - } - - hci_connect_cfm(conn, ev->status); - rcu_read_unlock(); - hci_conn_del(conn); - rcu_read_lock(); + conn->state = BT_CONNECTED; + set_bit(HCI_CONN_BIG_CREATED, &conn->flags); + hci_debugfs_create_conn(conn); + hci_conn_add_sysfs(conn); + hci_iso_setup_path(conn); }
- rcu_read_unlock(); - if (!ev->status && !i) /* If no BISes have been connected for the BIG, * terminate. This is in case all bound connections