BUG: workqueue leaked atomic, lock or RCU: kworker/u9:3[6379] preempt=0x00000000 lock=0->1 RCU=0->0 workfn=hci_rx_work 1 lock held by kworker/u9:3/6379: #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_conless_channel net/bluetooth/l2cap_core.c:6764 [inline] #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_recv_frame+0x610/0xc934 net/bluetooth/l2cap_core.c:6830 CPU: 0 PID: 6379 Comm: kworker/u9:3 Not tainted 6.10.0-rc7-syzkaller-gc912bf709078 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 process_one_work+0xdc0/0x15b8 kernel/workqueue.c:3269 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x938/0xecc kernel/workqueue.c:3409 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 ====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc7-syzkaller-gc912bf709078 #0 Not tainted ------------------------------------------------------ kworker/u9:3/6379 is trying to acquire lock: ffff0000d7be7948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x624/0x15b8 kernel/workqueue.c:3222 but task is already holding lock: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_conless_channel net/bluetooth/l2cap_core.c:6764 [inline] ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_recv_frame+0x610/0xc934 net/bluetooth/l2cap_core.c:6830 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&chan->lock/1){+.+.}-{3:3}: __lock_release kernel/locking/lockdep.c:5468 [inline] lock_release+0x334/0x9b8 kernel/locking/lockdep.c:5774 process_one_work+0x8a0/0x15b8 kernel/workqueue.c:3255 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x938/0xecc kernel/workqueue.c:3409 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #0 ((wq_completion)hci0#2){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5754 process_one_work+0x668/0x15b8 kernel/workqueue.c:3223 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x938/0xecc kernel/workqueue.c:3409 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&chan->lock/1); lock((wq_completion)hci0#2); lock(&chan->lock/1); lock((wq_completion)hci0#2); *** DEADLOCK *** 1 lock held by kworker/u9:3/6379: #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_conless_channel net/bluetooth/l2cap_core.c:6764 [inline] #0: ffff0000ebe43518 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_recv_frame+0x610/0xc934 net/bluetooth/l2cap_core.c:6830 stack backtrace: CPU: 0 PID: 6379 Comm: kworker/u9:3 Not tainted 6.10.0-rc7-syzkaller-gc912bf709078 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060 check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5754 process_one_work+0x668/0x15b8 kernel/workqueue.c:3223 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x938/0xecc kernel/workqueue.c:3409 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 BUG: workqueue leaked atomic, lock or RCU: kworker/u9:3[6379] preempt=0x00000000 lock=1->0 RCU=0->0 workfn=hci_rx_work INFO: lockdep is turned off. CPU: 0 PID: 6379 Comm: kworker/u9:3 Not tainted 6.10.0-rc7-syzkaller-gc912bf709078 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 process_one_work+0xdc0/0x15b8 kernel/workqueue.c:3269 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x938/0xecc kernel/workqueue.c:3409 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Bluetooth: hci2: command tx timeout Bluetooth: hci0: Controller not accepting commands anymore: ncmd = 0 Bluetooth: hci0: Injecting HCI hardware error event Bluetooth: hci0: hardware error 0x00 Bluetooth: hci0: Opcode 0x0c03 failed: -110