Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) ============================================ WARNING: possible recursive locking detected 4.19.191-syzkaller #0 Not tainted -------------------------------------------- syz-executor298/12417 is trying to acquire lock: 000000001f08d6b7 (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: 000000001f08d6b7 (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-executor298/12417: #0: 000000001f08d6b7 (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: 12417 Comm: syz-executor298 Not tainted 4.19.191-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:928 [inline] __mutex_lock+0xd7/0x1260 kernel/locking/mutex.c:1075 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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 __do_sys_exit_group kernel/exit.c:978 [inline] __se_sys_exit_group kernel/exit.c:976 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:976 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43e9f9 Code: Bad RIP value. RSP: 002b:00007fffd0467a28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000004b02f0 RCX: 000000000043e9f9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004b02f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001