====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc4-syzkaller-00390-g5dc4c995db9e #0 Not tainted ------------------------------------------------------ syz-executor.0/5541 is trying to acquire lock: ffff888028394130 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1725 [inline] ffff888028394130 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x6d/0x3a0 net/bluetooth/rfcomm/sock.c:73 but task is already holding lock: ffff8880776fd928 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x15d/0x890 net/bluetooth/rfcomm/core.c:487 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&d->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 __rfcomm_dlc_close+0x15d/0x890 net/bluetooth/rfcomm/core.c:487 rfcomm_dlc_close+0x1e9/0x240 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x13c/0x250 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xd8/0x230 net/bluetooth/rfcomm/sock.c:907 rfcomm_sock_release+0x68/0x140 net/bluetooth/rfcomm/sock.c:928 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x2450 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (rfcomm_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 rfcomm_dlc_open+0x93/0xa80 net/bluetooth/rfcomm/core.c:425 rfcomm_sock_connect+0x329/0x450 net/bluetooth/rfcomm/sock.c:413 __sys_connect_file+0x153/0x1a0 net/socket.c:1976 __sys_connect+0x165/0x1a0 net/socket.c:1993 __do_sys_connect net/socket.c:2003 [inline] __se_sys_connect net/socket.c:2000 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:2000 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3470 lock_sock include/net/sock.h:1725 [inline] rfcomm_sk_state_change+0x6d/0x3a0 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x1b1/0x890 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0x1e9/0x240 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x13c/0x250 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xd8/0x230 net/bluetooth/rfcomm/sock.c:907 rfcomm_sock_release+0x68/0x140 net/bluetooth/rfcomm/sock.c:928 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x2450 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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 *** 3 locks held by syz-executor.0/5541: #0: ffff88807080d610 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] #0: ffff88807080d610 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:649 #1: ffffffff8e313a08 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x33/0x240 net/bluetooth/rfcomm/core.c:507 #2: ffff8880776fd928 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x15d/0x890 net/bluetooth/rfcomm/core.c:487 stack backtrace: CPU: 1 PID: 5541 Comm: syz-executor.0 Not tainted 6.2.0-rc4-syzkaller-00390-g5dc4c995db9e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3470 lock_sock include/net/sock.h:1725 [inline] rfcomm_sk_state_change+0x6d/0x3a0 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x1b1/0x890 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0x1e9/0x240 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x13c/0x250 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xd8/0x230 net/bluetooth/rfcomm/sock.c:907 rfcomm_sock_release+0x68/0x140 net/bluetooth/rfcomm/sock.c:928 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x2450 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7edfe89049 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7ee1010168 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f7edff9bf60 RCX: 00007f7edfe89049 RDX: 0000000000000080 RSI: 00000000200001c0 RDI: 0000000000000004 RBP: 00007f7edfee308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc08ec3af R14: 00007f7ee1010300 R15: 0000000000022000