============================================ WARNING: possible recursive locking detected 6.0.0-rc6-syzkaller-00009-g60891ec99e14 #0 Not tainted -------------------------------------------- syz-executor.2/16585 is trying to acquire lock: ffffffff8d4f9d78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x12e/0x12f0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 but task is already holding lock: ffffffff8d4f9d78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x12e/0x12f0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 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.2/16585: #0: ffffffff8d4f9d78 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x12e/0x12f0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 stack backtrace: CPU: 1 PID: 16585 Comm: syz-executor.2 Not tainted 6.0.0-rc6-syzkaller-00009-g60891ec99e14 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain+0x4897/0x6600 kernel/locking/lockdep.c:3816 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5666 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 vmci_qp_broker_detach+0x12e/0x12f0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:444 [inline] kref_put include/linux/kref.h:65 [inline] vmci_ctx_put+0x7d2/0xef0 drivers/misc/vmw_vmci/vmci_context.c:497 vmci_ctx_enqueue_datagram+0x3a7/0x440 drivers/misc/vmw_vmci/vmci_context.c:360 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:275 [inline] vmci_datagram_dispatch+0x458/0xc00 drivers/misc/vmw_vmci/vmci_datagram.c:339 qp_notify_peer drivers/misc/vmw_vmci/vmci_queue_pair.c:1479 [inline] vmci_qp_broker_detach+0xb97/0x12f0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2186 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:444 [inline] kref_put include/linux/kref.h:65 [inline] vmci_ctx_put+0x7d2/0xef0 drivers/misc/vmw_vmci/vmci_context.c:497 vmci_host_close+0x96/0x160 drivers/misc/vmw_vmci/vmci_host.c:143 __fput+0x3b9/0x820 fs/file_table.c:320 task_work_run+0x146/0x1c0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:169 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f412443c04b 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:00007ffc261d0450 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f412443c04b RDX: 00007f41245a0828 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007f412459d980 R08: 0000000000000000 R09: 00007f41245a0830 R10: 00007ffc261d0550 R11: 0000000000000293 R12: 00000000000e5203 R13: 00007ffc261d0550 R14: 00007f412459bf80 R15: 0000000000000032