======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc2-syzkaller-00100-geb952c47d154 #0 Not tainted
------------------------------------------------------
syz.1.1732/13805 is trying to acquire lock:
ffff888021337258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline]
ffff888021337258 (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:
ffff88802f59f528 (&d->lock#2){+.+.}-{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#2){+.+.}-{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_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491
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+0xbe/0x240 net/socket.c:1426
__fput+0x241/0x880 fs/file_table.c:431
task_work_run+0x251/0x310 kernel/task_work.c:228
get_signal+0x15e8/0x1740 kernel/signal.c:2690
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (rfcomm_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_dlc_exists+0xa6/0x380 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+0xb53/0x2220 net/bluetooth/rfcomm/tty.c:584
rfcomm_sock_ioctl+0x86/0xd0 net/bluetooth/rfcomm/sock.c:869
sock_do_ioctl+0x15a/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+0xfb/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_create_dev net/bluetooth/rfcomm/tty.c:484 [inline]
rfcomm_dev_ioctl+0x237/0x2220 net/bluetooth/rfcomm/tty.c:584
rfcomm_sock_ioctl+0x86/0xd0 net/bluetooth/rfcomm/sock.c:869
sock_do_ioctl+0x15a/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+0xfb/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+0x271/0x6a0 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+0xbe/0x240 net/socket.c:1426
__fput+0x241/0x880 fs/file_table.c:431
task_work_run+0x251/0x310 kernel/task_work.c:228
get_signal+0x15e8/0x1740 kernel/signal.c:2690
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM --> rfcomm_mutex --> &d->lock#2
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&d->lock#2);
lock(rfcomm_mutex);
lock(&d->lock#2);
lock(sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM);
*** DEADLOCK ***
3 locks held by syz.1.1732/13805:
#0: ffff88807b4a1408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
#0: ffff88807b4a1408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:657 [inline]
#0: ffff88807b4a1408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1426
#1: ffffffff8fe5fdc8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x3b/0x190 net/bluetooth/rfcomm/core.c:511
#2: ffff88802f59f528 (&d->lock#2){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491
stack backtrace:
CPU: 0 UID: 0 PID: 13805 Comm: syz.1.1732 Not tainted 6.12.0-rc2-syzkaller-00100-geb952c47d154 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__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+0x271/0x6a0 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+0xbe/0x240 net/socket.c:1426
__fput+0x241/0x880 fs/file_table.c:431
task_work_run+0x251/0x310 kernel/task_work.c:228
get_signal+0x15e8/0x1740 kernel/signal.c:2690
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd88937dff9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd88a08e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007fd889535f80 RCX: 00007fd88937dff9
RDX: 0000000000000080 RSI: 0000000020000300 RDI: 0000000000000007
RBP: 00007fd8893f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd889535f80 R15: 00007ffdbebb4c38
</TASK>