============================================ WARNING: possible recursive locking detected 6.2.0-rc5-syzkaller #0 Not tainted -------------------------------------------- syz-executor122/15321 is trying to acquire lock: ffffffff8bcdda78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x11e/0x13a0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 but task is already holding lock: ffffffff8bcdda78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x11e/0x13a0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 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-executor122/15321: #0: ffffffff8bcdda78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x11e/0x13a0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 stack backtrace: CPU: 1 PID: 15321 Comm: syz-executor122 Not tainted 6.2.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x5b/0x81 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 vmci_qp_broker_detach+0x11e/0x13a0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 ctx_free_ctx+0x410/0xc10 drivers/misc/vmw_vmci/vmci_context.c:444 kref_put include/linux/kref.h:65 [inline] vmci_ctx_put drivers/misc/vmw_vmci/vmci_context.c:497 [inline] vmci_ctx_enqueue_datagram+0x3e2/0x530 drivers/misc/vmw_vmci/vmci_context.c:360 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:275 [inline] vmci_datagram_dispatch+0x274/0x8b0 drivers/misc/vmw_vmci/vmci_datagram.c:339 qp_notify_peer+0x147/0x200 drivers/misc/vmw_vmci/vmci_queue_pair.c:1481 vmci_qp_broker_detach+0x863/0x13a0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2188 ctx_free_ctx+0x410/0xc10 drivers/misc/vmw_vmci/vmci_context.c:444 vmci_host_close+0xf6/0x180 drivers/misc/vmw_vmci/vmci_host.c:143 __fput+0x1fa/0x9a0 fs/file_table.c:320 task_work_run+0x12f/0x220 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x916/0x2460 kernel/exit.c:867 do_group_exit+0xb4/0x250 kernel/exit.c:1012 get_signal+0x1c53/0x1ea0 kernel/signal.c:2859 arch_do_signal_or_restart+0x79/0x5a0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0x80 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3116f5aa19 Code: Unable to access opcode bytes at 0x7f3116f5a9ef. RSP: 002b:00007f3116f0c308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f3116fe23e8 RCX: 00007f3116f5aa19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3116fe23e8 RBP: 00007f3116fe23e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3116fe23ec R13: 00007f3116fb0064 R14: 636d762f7665642f R15: 0000000000022000