[v3,0/2] Bluetooth: fix inconsistent lock states

Message

Desmond Cheong Zhi Xi July 21, 2021, 9:38 a.m. UTC

Hi,

This series addresses inconsistent lock states first identified by
Syzbot here:
https://syzkaller.appspot.com/bug?extid=2f6d7c28bb4bf7e82060

v2 -> v3:
- Split SCO and RFCOMM code changes, as suggested by Luiz Augusto von
Dentz.
- Simplify local bh disabling in SCO by using local_bh_disable/enable
inside sco_chan_del. The rationale is inside the commit message, but in
summary I initially wanted to avoid nesting local_bh_disable until I
learned that local_bh_disable/enable pairs are reentrant.

v1 -> v2:
- Instead of pulling out the clean-up code out from sco_chan_del and
using it directly in sco_conn_del, disable local softirqs for relevant
sections.
- Disable local softirqs more thoroughly for instances of
bh_lock_sock/bh_lock_sock_nested in the bluetooth subsystem.
Specifically, the calls in af_bluetooth.c and rfcomm/sock.c are now made
with local softirqs disabled as well.

Best wishes,
Desmond

Desmond Cheong Zhi Xi (2):
  Bluetooth: fix inconsistent lock state in SCO
  Bluetooth: fix inconsistent lock state in rfcomm_connect_ind

 net/bluetooth/rfcomm/sock.c |  2 ++
 net/bluetooth/sco.c         | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+)