====================================================== WARNING: possible circular locking dependency detected 5.15.137-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor236/4000 is trying to acquire lock: ffff0000d6600120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] ffff0000d6600120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x60/0x2c8 net/bluetooth/rfcomm/sock.c:73 but task is already holding lock: ffff0000d5502528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x200/0x634 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}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 __rfcomm_dlc_close+0x200/0x634 net/bluetooth/rfcomm/core.c:487 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:912 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:933 __sock_release net/socket.c:649 [inline] sock_close+0xb8/0x1fc net/socket.c:1334 __fput+0x30c/0x7f0 fs/file_table.c:280 ____fput+0x20/0x30 fs/file_table.c:308 task_work_run+0x130/0x1e4 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x688/0x2134 kernel/exit.c:872 do_group_exit+0x110/0x268 kernel/exit.c:994 get_signal+0x634/0x1550 kernel/signal.c:2889 do_signal arch/arm64/kernel/signal.c:890 [inline] do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #2 (rfcomm_mutex){+.+.}-{3:3}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 rfcomm_dlc_exists+0xb0/0x32c net/bluetooth/rfcomm/core.c:542 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:415 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline] rfcomm_dev_ioctl+0x938/0x2434 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x98/0xf0 net/bluetooth/rfcomm/sock.c:880 sock_do_ioctl+0x134/0x2dc net/socket.c:1138 sock_ioctl+0x4f0/0x8ac net/socket.c:1255 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #1 (rfcomm_ioctl_mutex){+.+.}-{3:3}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:485 [inline] rfcomm_dev_ioctl+0x258/0x2434 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x98/0xf0 net/bluetooth/rfcomm/sock.c:880 sock_do_ioctl+0x134/0x2dc net/socket.c:1138 sock_ioctl+0x4f0/0x8ac net/socket.c:1255 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3787 [inline] __lock_acquire+0x32cc/0x7620 kernel/locking/lockdep.c:5011 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622 lock_sock_nested+0xec/0x1ec net/core/sock.c:3231 lock_sock include/net/sock.h:1668 [inline] rfcomm_sk_state_change+0x60/0x2c8 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x23c/0x634 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:912 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:933 __sock_release net/socket.c:649 [inline] sock_close+0xb8/0x1fc net/socket.c:1334 __fput+0x30c/0x7f0 fs/file_table.c:280 ____fput+0x20/0x30 fs/file_table.c:308 task_work_run+0x130/0x1e4 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x688/0x2134 kernel/exit.c:872 do_group_exit+0x110/0x268 kernel/exit.c:994 get_signal+0x634/0x1550 kernel/signal.c:2889 do_signal arch/arm64/kernel/signal.c:890 [inline] do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 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-executor236/4000: #0: ffff0000df0b8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff0000df0b8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline] #0: ffff0000df0b8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x80/0x1fc net/socket.c:1334 #1: ffff800016b6cb08 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x44/0x194 net/bluetooth/rfcomm/core.c:507 #2: ffff0000d5502528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x200/0x634 net/bluetooth/rfcomm/core.c:487 stack backtrace: CPU: 0 PID: 4000 Comm: syz-executor236 Not tainted 5.15.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3787 [inline] __lock_acquire+0x32cc/0x7620 kernel/locking/lockdep.c:5011 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622 lock_sock_nested+0xec/0x1ec net/core/sock.c:3231 lock_sock include/net/sock.h:1668 [inline] rfcomm_sk_state_change+0x60/0x2c8 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x23c/0x634 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:912 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:933 __sock_release net/socket.c:649 [inline] sock_close+0xb8/0x1fc net/socket.c:1334 __fput+0x30c/0x7f0 fs/file_table.c:280 ____fput+0x20/0x30 fs/file_table.c:308 task_work_run+0x130/0x1e4 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x688/0x2134 kernel/exit.c:872 do_group_exit+0x110/0x268 kernel/exit.c:994 get_signal+0x634/0x1550 kernel/signal.c:2889 do_signal arch/arm64/kernel/signal.c:890 [inline] do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584