============================================ WARNING: possible recursive locking detected 6.1.148-syzkaller #0 Not tainted -------------------------------------------- syz.3.103/4810 is trying to acquire lock: ffffffff8d3e9c38 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x110/0xef0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 but task is already holding lock: ffffffff8d3e9c38 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x110/0xef0 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.3.103/4810: #0: ffffffff8d3e9c38 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x110/0xef0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 stack backtrace: CPU: 0 PID: 4810 Comm: syz.3.103 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 __lock_acquire+0x122f/0x7c50 kernel/locking/lockdep.c:-1 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 vmci_qp_broker_detach+0x110/0xef0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:444 [inline] kref_put include/linux/kref.h:65 [inline] vmci_ctx_put+0x5ec/0xc00 drivers/misc/vmw_vmci/vmci_context.c:497 vmci_ctx_enqueue_datagram+0x3a7/0x420 drivers/misc/vmw_vmci/vmci_context.c:360 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:276 [inline] vmci_datagram_dispatch+0x438/0xbc0 drivers/misc/vmw_vmci/vmci_datagram.c:340 qp_notify_peer drivers/misc/vmw_vmci/vmci_queue_pair.c:1481 [inline] vmci_qp_broker_detach+0x8b5/0xef0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2188 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:444 [inline] kref_put include/linux/kref.h:65 [inline] vmci_ctx_put+0x5ec/0xc00 drivers/misc/vmw_vmci/vmci_context.c:497 vmci_host_close+0x97/0x160 drivers/misc/vmw_vmci/vmci_host.c:143 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f755bd8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc02d6e5b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f755bfb7da0 RCX: 00007f755bd8ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f755bfb7da0 R08: 00000000000005d4 R09: 0000000f02d6e8af R10: 00007f755bfb7cb0 R11: 0000000000000246 R12: 0000000000020bef R13: 00007f755bfb6090 R14: ffffffffffffffff R15: 00007ffc02d6e6d0