syzbot

============================================
WARNING: possible recursive locking detected
6.14.0-rc4-syzkaller #0 Not tainted
--------------------------------------------
syz-executor236/6513 is trying to acquire lock:
ffffffff8f512358 (qp_broker_list.mutex){+.+.}-{4:4}, at: vmci_qp_broker_detach+0xf5/0x11d0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095

but task is already holding lock:
ffffffff8f512358 (qp_broker_list.mutex){+.+.}-{4:4}, at: vmci_qp_broker_detach+0xf5/0x11d0 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-executor236/6513:
 #0: ffffffff8f512358 (qp_broker_list.mutex){+.+.}-{4:4}, at: vmci_qp_broker_detach+0xf5/0x11d0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2095

stack backtrace:
CPU: 1 UID: 0 PID: 6513 Comm: syz-executor236 Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039
 check_deadlock kernel/locking/lockdep.c:3091 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
 vmci_qp_broker_detach+0xf5/0x11d0 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+0x807/0xe40 drivers/misc/vmw_vmci/vmci_context.c:497
 vmci_ctx_enqueue_datagram+0x392/0x430 drivers/misc/vmw_vmci/vmci_context.c:360
 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:276 [inline]
 vmci_datagram_dispatch+0x447/0xc50 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+0xb4e/0x11d0 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+0x807/0xe40 drivers/misc/vmw_vmci/vmci_context.c:497
 vmci_host_close+0x98/0x160 drivers/misc/vmw_vmci/vmci_host.c:143
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c8153fdf9
Code: Unable to access opcode bytes at 0x7f0c8153fdcf.
RSP: 002b:00007ffff59a1f68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0c8153fdf9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f0c815bb2b0 R08: ffffffffffffffb8 R09: 00000000000000a0
R10: 00000000000000a0 R11: 0000000000000246 R12: 00007f0c815bb2b0
R13: 0000000000000000 R14: 00007f0c815bbd20 R15: 00007f0c81510fa0
 </TASK>