Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10)
Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10)
Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10)
============================================
WARNING: possible recursive locking detected
4.19.211-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.3/19599 is trying to acquire lock:
0000000044e00d33 (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099

but task is already holding lock:
0000000044e00d33 (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(qp_broker_list.mutex);
  lock(qp_broker_list.mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by syz-executor.3/19599:
 #0: 0000000044e00d33 (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099

stack backtrace:
CPU: 0 PID: 19599 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_deadlock_bug kernel/locking/lockdep.c:1764 [inline]
 check_deadlock kernel/locking/lockdep.c:1808 [inline]
 validate_chain kernel/locking/lockdep.c:2404 [inline]
 __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 __mutex_lock_common kernel/locking/mutex.c:937 [inline]
 __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078
 vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099
 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:452 [inline]
 kref_put include/linux/kref.h:70 [inline]
 vmci_ctx_put+0x55a/0xd60 drivers/misc/vmw_vmci/vmci_context.c:505
 vmci_ctx_enqueue_datagram+0x3f7/0x500 drivers/misc/vmw_vmci/vmci_context.c:368
 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:283 [inline]
 vmci_datagram_dispatch+0x39b/0xb40 drivers/misc/vmw_vmci/vmci_datagram.c:347
 qp_notify_peer+0x182/0x260 drivers/misc/vmw_vmci/vmci_queue_pair.c:1488
 vmci_qp_broker_detach+0xa09/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2192
 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:452 [inline]
 kref_put include/linux/kref.h:70 [inline]
 vmci_ctx_put+0x55a/0xd60 drivers/misc/vmw_vmci/vmci_context.c:505
 vmci_host_close+0x116/0x1a0 drivers/misc/vmw_vmci/vmci_host.c:147
 __fput+0x2ce/0x890 fs/file_table.c:278
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fbe41e0bc8b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffc99498d10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007fbe41e0bc8b
RDX: 00007fbe41f70418 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007fbe41f6d960 R08: 0000000000000000 R09: 00007fbe41f70420
R10: 00007ffc99498e10 R11: 0000000000000293 R12: 000000000005665c
R13: 00007ffc99498e10 R14: 00007fbe41f6bf60 R15: 0000000000000032