====================================================== WARNING: possible circular locking dependency detected 6.1.104-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:11/3785 is trying to acquire lock: ffff88807b572130 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1748 [inline] ffff88807b572130 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x57/0x300 net/bluetooth/rfcomm/sock.c:73 but task is already holding lock: ffff888058368d28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x259/0x6d0 net/bluetooth/rfcomm/core.c:487 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&d->lock){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747 __rfcomm_dlc_close+0x259/0x6d0 net/bluetooth/rfcomm/core.c:487 rfcomm_dlc_close+0xed/0x180 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x104/0x220 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xb4/0x230 net/bluetooth/rfcomm/sock.c:905 rfcomm_sock_release+0x55/0x110 net/bluetooth/rfcomm/sock.c:926 __sock_release net/socket.c:654 [inline] sock_close+0xcd/0x230 net/socket.c:1400 __fput+0x3f6/0x8d0 fs/file_table.c:320 delayed_fput+0x55/0x80 fs/file_table.c:343 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #2 (rfcomm_mutex){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747 rfcomm_dlc_exists+0xa2/0x370 net/bluetooth/rfcomm/core.c:542 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:414 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:485 [inline] rfcomm_dev_ioctl+0xb2d/0x2180 net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x82/0xc0 net/bluetooth/rfcomm/sock.c:873 sock_do_ioctl+0x152/0x450 net/socket.c:1204 sock_ioctl+0x47f/0x770 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (rfcomm_ioctl_mutex){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:484 [inline] rfcomm_dev_ioctl+0x233/0x2180 net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x82/0xc0 net/bluetooth/rfcomm/sock.c:873 sock_do_ioctl+0x152/0x450 net/socket.c:1204 sock_ioctl+0x47f/0x770 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 lock_sock_nested+0x44/0x100 net/core/sock.c:3485 lock_sock include/net/sock.h:1748 [inline] rfcomm_sk_state_change+0x57/0x300 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x2b2/0x6d0 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0xed/0x180 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x104/0x220 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xb4/0x230 net/bluetooth/rfcomm/sock.c:905 rfcomm_sock_release+0x55/0x110 net/bluetooth/rfcomm/sock.c:926 __sock_release net/socket.c:654 [inline] sock_close+0xcd/0x230 net/socket.c:1400 __fput+0x3f6/0x8d0 fs/file_table.c:320 delayed_fput+0x55/0x80 fs/file_table.c:343 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM --> rfcomm_mutex --> &d->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&d->lock); lock(rfcomm_mutex); lock(&d->lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM); *** DEADLOCK *** 5 locks held by kworker/0:11/3785: #0: ffff888012870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004867d20 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffff888071123810 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #2: ffff888071123810 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #2: ffff888071123810 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x98/0x230 net/socket.c:1400 #3: ffffffff8e673528 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x37/0x180 net/bluetooth/rfcomm/core.c:507 #4: ffff888058368d28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x259/0x6d0 net/bluetooth/rfcomm/core.c:487 stack backtrace: CPU: 0 PID: 3785 Comm: kworker/0:11 Not tainted 6.1.104-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: events delayed_fput Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 lock_sock_nested+0x44/0x100 net/core/sock.c:3485 lock_sock include/net/sock.h:1748 [inline] rfcomm_sk_state_change+0x57/0x300 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x2b2/0x6d0 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0xed/0x180 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x104/0x220 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xb4/0x230 net/bluetooth/rfcomm/sock.c:905 rfcomm_sock_release+0x55/0x110 net/bluetooth/rfcomm/sock.c:926 __sock_release net/socket.c:654 [inline] sock_close+0xcd/0x230 net/socket.c:1400 __fput+0x3f6/0x8d0 fs/file_table.c:320 delayed_fput+0x55/0x80 fs/file_table.c:343 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 usb 4-1: new high-speed USB device number 13 using dummy_hcd usb 4-1: Using ep0 maxpacket: 16 usb 4-1: config 0 interface 0 altsetting 0 endpoint 0xF has invalid wMaxPacketSize 0 usb 4-1: config 0 interface 0 altsetting 0 bulk endpoint 0xF has invalid maxpacket 0 usb 4-1: config 0 interface 0 altsetting 0 endpoint 0x82 has invalid wMaxPacketSize 0 usb 4-1: New USB device found, idVendor=054c, idProduct=06c1, bcdDevice=c2.87 usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 4-1: Product: syz usb 4-1: Manufacturer: syz usb 4-1: SerialNumber: syz usb 4-1: config 0 descriptor?? port100 4-1:0.0: NFC: Could not find bulk-in or bulk-out endpoint