alistair23-linux/include/net/bluetooth
Matthias Kaehlcke c4f5627f7e Bluetooth: Fix locking in bt_accept_enqueue() for BH context
With commit e163376220 ("Bluetooth: Handle bt_accept_enqueue() socket
atomically") lock_sock[_nested]() is used to acquire the socket lock
before manipulating the socket. lock_sock[_nested]() may block, which
is problematic since bt_accept_enqueue() can be called in bottom half
context (e.g. from rfcomm_connect_ind()):

[<ffffff80080d81ec>] __might_sleep+0x4c/0x80
[<ffffff800876c7b0>] lock_sock_nested+0x24/0x58
[<ffffff8000d7c27c>] bt_accept_enqueue+0x48/0xd4 [bluetooth]
[<ffffff8000e67d8c>] rfcomm_connect_ind+0x190/0x218 [rfcomm]

Add a parameter to bt_accept_enqueue() to indicate whether the
function is called from BH context, and acquire the socket lock
with bh_lock_sock_nested() if that's the case.

Also adapt all callers of bt_accept_enqueue() to pass the new
parameter:

- l2cap_sock_new_connection_cb()
  - uses lock_sock() to lock the parent socket => process context

- rfcomm_connect_ind()
  - acquires the parent socket lock with bh_lock_sock() => BH
    context

- __sco_chan_add()
  - called from sco_chan_add(), which is called from sco_connect().
    parent is NULL, hence bt_accept_enqueue() isn't called in this
    code path and we can ignore it
  - also called from sco_conn_ready(). uses bh_lock_sock() to acquire
    the parent lock => BH context

Fixes: e163376220 ("Bluetooth: Handle bt_accept_enqueue() socket atomically")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
2019-01-22 09:51:20 +01:00
..
bluetooth.h Bluetooth: Fix locking in bt_accept_enqueue() for BH context 2019-01-22 09:51:20 +01:00
hci.h Bluetooth: Add definitions and track LE resolve list modification 2018-09-27 12:38:52 +02:00
hci_core.h Bluetooth: Fix debugfs NULL pointer dereference 2018-09-28 20:53:48 +02:00
hci_mon.h
hci_sock.h
l2cap.h Bluetooth: Errata Service Release 8, Erratum 3253 2018-10-14 10:25:47 +02:00
mgmt.h Bluetooth: Implement secondary advertising on different PHYs 2018-07-30 13:44:53 +02:00
rfcomm.h Bluetooth: convert rfcomm_dlc.refcnt from atomic_t to refcount_t 2017-04-12 22:02:36 +02:00
sco.h