====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc4-syzkaller-g6a71d2909427 #0 Not tainted ------------------------------------------------------ syz-executor312/6266 is trying to acquire lock: ffff0000dd5ed258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline] ffff0000dd5ed258 (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: ffff0000ded39528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x1f8/0x608 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}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 __rfcomm_dlc_close+0x1f8/0x608 net/bluetooth/rfcomm/core.c:491 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:524 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:901 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:922 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:422 ____fput+0x20/0x30 fs/file_table.c:450 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x4e4/0x1ac8 kernel/exit.c:878 do_group_exit+0x194/0x22c kernel/exit.c:1027 get_signal+0x1414/0x1530 kernel/signal.c:2911 do_signal+0x238/0x3e8c arch/arm64/kernel/signal.c:1308 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 -> #2 (rfcomm_mutex){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 rfcomm_dlc_exists+0xb0/0x32c net/bluetooth/rfcomm/core.c:546 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:414 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:485 [inline] rfcomm_dev_ioctl+0x888/0x22ac net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x98/0xf0 net/bluetooth/rfcomm/sock.c:869 sock_do_ioctl+0x134/0x2d0 net/socket.c:1222 sock_ioctl+0x4ec/0x838 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 -> #1 (rfcomm_ioctl_mutex){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:484 [inline] rfcomm_dev_ioctl+0x258/0x22ac net/bluetooth/rfcomm/tty.c:587 rfcomm_sock_ioctl+0x98/0xf0 net/bluetooth/rfcomm/sock.c:869 sock_do_ioctl+0x134/0x2d0 net/socket.c:1222 sock_ioctl+0x4ec/0x838 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 lock_sock_nested+0x5c/0x11c net/core/sock.c:3535 lock_sock include/net/sock.h:1671 [inline] rfcomm_sk_state_change+0x60/0x2c8 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x234/0x608 net/bluetooth/rfcomm/core.c:493 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:524 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:901 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:922 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:422 ____fput+0x20/0x30 fs/file_table.c:450 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x4e4/0x1ac8 kernel/exit.c:878 do_group_exit+0x194/0x22c kernel/exit.c:1027 get_signal+0x1414/0x1530 kernel/signal.c:2911 do_signal+0x238/0x3e8c arch/arm64/kernel/signal.c:1308 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 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-executor312/6266: #0: ffff0000df557410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline] #0: ffff0000df557410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff0000df557410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x80/0x1e8 net/socket.c:1421 #1: ffff800091d4e268 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x44/0x194 net/bluetooth/rfcomm/core.c:511 #2: ffff0000ded39528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x1f8/0x608 net/bluetooth/rfcomm/core.c:491 stack backtrace: CPU: 1 PID: 6266 Comm: syz-executor312 Not tainted 6.9.0-rc4-syzkaller-g6a71d2909427 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060 check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 lock_sock_nested+0x5c/0x11c net/core/sock.c:3535 lock_sock include/net/sock.h:1671 [inline] rfcomm_sk_state_change+0x60/0x2c8 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x234/0x608 net/bluetooth/rfcomm/core.c:493 rfcomm_dlc_close+0x100/0x194 net/bluetooth/rfcomm/core.c:524 __rfcomm_sock_close+0x138/0x258 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xa8/0x214 net/bluetooth/rfcomm/sock.c:901 rfcomm_sock_release+0x58/0x114 net/bluetooth/rfcomm/sock.c:922 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:422 ____fput+0x20/0x30 fs/file_table.c:450 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x4e4/0x1ac8 kernel/exit.c:878 do_group_exit+0x194/0x22c kernel/exit.c:1027 get_signal+0x1414/0x1530 kernel/signal.c:2911 do_signal+0x238/0x3e8c arch/arm64/kernel/signal.c:1308 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598