====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 Not tainted ------------------------------------------------------ kworker/1:5/15832 is trying to acquire lock: ffff8880619e8258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline] ffff8880619e8258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73 but task is already holding lock: ffff888012dc3528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&d->lock){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 __rfcomm_dev_add net/bluetooth/rfcomm/tty.c:277 [inline] rfcomm_dev_add net/bluetooth/rfcomm/tty.c:325 [inline] __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:424 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:485 [inline] rfcomm_dev_ioctl+0x1461/0x2220 net/bluetooth/rfcomm/tty.c:584 rfcomm_sock_ioctl+0x86/0xd0 net/bluetooth/rfcomm/sock.c:869 sock_do_ioctl+0x158/0x460 net/socket.c:1227 sock_ioctl+0x626/0x8e0 net/socket.c:1346 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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 -> #2 (rfcomm_dev_lock){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 rfcomm_dev_get+0x81/0x380 net/bluetooth/rfcomm/tty.c:163 __rfcomm_release_dev net/bluetooth/rfcomm/tty.c:448 [inline] rfcomm_release_dev net/bluetooth/rfcomm/tty.c:496 [inline] rfcomm_dev_ioctl+0x429/0x2220 net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x86/0xd0 net/bluetooth/rfcomm/sock.c:869 sock_do_ioctl+0x158/0x460 net/socket.c:1227 sock_ioctl+0x626/0x8e0 net/socket.c:1346 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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 -> #1 (rfcomm_ioctl_mutex){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 rfcomm_release_dev net/bluetooth/rfcomm/tty.c:495 [inline] rfcomm_dev_ioctl+0x168/0x2220 net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x86/0xd0 net/bluetooth/rfcomm/sock.c:869 sock_do_ioctl+0x158/0x460 net/socket.c:1227 sock_ioctl+0x626/0x8e0 net/socket.c:1346 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 lock_sock_nested+0x48/0x100 net/core/sock.c:3611 lock_sock include/net/sock.h:1609 [inline] rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x26f/0x6a0 net/bluetooth/rfcomm/core.c:493 rfcomm_dlc_close+0xf1/0x190 net/bluetooth/rfcomm/core.c:524 __rfcomm_sock_close+0x121/0x250 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xb8/0x240 net/bluetooth/rfcomm/sock.c:901 rfcomm_sock_release+0x59/0x120 net/bluetooth/rfcomm/sock.c:922 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 delayed_fput+0x63/0x90 fs/file_table.c:454 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM --> rfcomm_dev_lock --> &d->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&d->lock); lock(rfcomm_dev_lock); lock(&d->lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM); *** DEADLOCK *** 5 locks held by kworker/1:5/15832: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900037cfd00 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900037cfd00 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff888057087a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #2: ffff888057087a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release net/socket.c:657 [inline] #2: ffff888057087a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1426 #3: ffffffff8fe4d8c8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x3b/0x190 net/bluetooth/rfcomm/core.c:511 #4: ffff888012dc3528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491 stack backtrace: CPU: 1 UID: 0 PID: 15832 Comm: kworker/1:5 Not tainted 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events delayed_fput Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 lock_sock_nested+0x48/0x100 net/core/sock.c:3611 lock_sock include/net/sock.h:1609 [inline] rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x26f/0x6a0 net/bluetooth/rfcomm/core.c:493 rfcomm_dlc_close+0xf1/0x190 net/bluetooth/rfcomm/core.c:524 __rfcomm_sock_close+0x121/0x250 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xb8/0x240 net/bluetooth/rfcomm/sock.c:901 rfcomm_sock_release+0x59/0x120 net/bluetooth/rfcomm/sock.c:922 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 delayed_fput+0x63/0x90 fs/file_table.c:454 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244