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70a13b1e25
commit 9a8ec9e8eb upstream.
This attempts to fix the following trace:
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc2-g0b93eeba4454 #4703 Not tainted
------------------------------------------------------
kworker/u3:0/46 is trying to acquire lock:
ffff888001fd9130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at:
sco_connect_cfm+0x118/0x4a0
but task is already holding lock:
ffffffff831e3340 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_sync_conn_complete_evt+0x1ad/0x3d0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (hci_cb_list_lock){+.+.}-{3:3}:
__mutex_lock+0x13b/0xcc0
hci_sync_conn_complete_evt+0x1ad/0x3d0
hci_event_packet+0x55c/0x7c0
hci_rx_work+0x34c/0xa00
process_one_work+0x575/0x910
worker_thread+0x89/0x6f0
kthread+0x14e/0x180
ret_from_fork+0x2b/0x50
-> #1 (&hdev->lock){+.+.}-{3:3}:
__mutex_lock+0x13b/0xcc0
sco_sock_connect+0xfc/0x630
__sys_connect+0x197/0x1b0
__x64_sys_connect+0x37/0x50
do_syscall_64+0x42/0x90
entry_SYSCALL_64_after_hwframe+0x70/0xda
-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
__lock_acquire+0x18cc/0x3740
lock_acquire+0x151/0x3a0
lock_sock_nested+0x32/0x80
sco_connect_cfm+0x118/0x4a0
hci_sync_conn_complete_evt+0x1e6/0x3d0
hci_event_packet+0x55c/0x7c0
hci_rx_work+0x34c/0xa00
process_one_work+0x575/0x910
worker_thread+0x89/0x6f0
kthread+0x14e/0x180
ret_from_fork+0x2b/0x50
other info that might help us debug this:
Chain exists of:
sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &hdev->lock --> hci_cb_list_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(hci_cb_list_lock);
lock(&hdev->lock);
lock(hci_cb_list_lock);
lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO);
*** DEADLOCK ***
4 locks held by kworker/u3:0/46:
#0: ffff8880028d1130 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
process_one_work+0x4c0/0x910
#1: ffff8880013dfde0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0},
at: process_one_work+0x4c0/0x910
#2: ffff8880025d8070 (&hdev->lock){+.+.}-{3:3}, at:
hci_sync_conn_complete_evt+0xa6/0x3d0
#3: ffffffffb79e3340 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_sync_conn_complete_evt+0x1ad/0x3d0
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
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