ERROR: (device loop8): remounting filesystem as read-only
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/7333 is trying to acquire lock:
ffff88801f922120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
ffff88801f922120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_del+0x142/0x360 net/bluetooth/sco.c:206
but task is already holding lock:
ffffffff8d582a28 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline]
ffffffff8d582a28 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (hci_cb_list_lock){+.+.}-{3:3}:
__mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
hci_connect_cfm include/net/bluetooth/hci_core.h:1502 [inline]
hci_remote_features_evt+0x5f5/0xa40 net/bluetooth/hci_event.c:3372
hci_event_packet+0x63a/0x1370 net/bluetooth/hci_event.c:6449
hci_rx_work+0x255/0xa10 net/bluetooth/hci_core.c:5164
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
-> #1 (&hdev->lock){+.+.}-{3:3}:
__mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
sco_sock_connect+0x18f/0x910 net/bluetooth/sco.c:604
__sys_connect_file net/socket.c:1932 [inline]
__sys_connect+0x3cb/0x450 net/socket.c:1949
__do_sys_connect net/socket.c:1959 [inline]
__se_sys_connect net/socket.c:1956 [inline]
__x64_sys_connect+0x76/0x80 net/socket.c:1956
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{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:3788 [inline]
__lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
lock_sock_nested+0x44/0x100 net/core/sock.c:3259
lock_sock include/net/sock.h:1744 [inline]
sco_conn_del+0x142/0x360 net/bluetooth/sco.c:206
hci_disconn_cfm include/net/bluetooth/hci_core.h:1520 [inline]
hci_conn_hash_flush+0x107/0x220 net/bluetooth/hci_conn.c:1622
hci_dev_do_close+0x991/0x1030 net/bluetooth/hci_core.c:1795
hci_unregister_dev+0x2d7/0x580 net/bluetooth/hci_core.c:4044
vhci_release+0x73/0xc0 drivers/bluetooth/hci_vhci.c:345
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
other info that might help us debug this:
Chain exists of:
sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &hdev->lock --> hci_cb_list_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(hci_cb_list_lock);
lock(&hdev->lock);
lock(hci_cb_list_lock);
lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO);
*** DEADLOCK ***
3 locks held by syz-executor/7333:
#0: ffff8880260f4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737
#1: ffff8880260f4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782
#2: ffffffff8d582a28 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline]
#2: ffffffff8d582a28 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
stack backtrace:
CPU: 0 PID: 7333 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
check_noncircular+0x296/0x330 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:3788 [inline]
__lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
lock_sock_nested+0x44/0x100 net/core/sock.c:3259
lock_sock include/net/sock.h:1744 [inline]
sco_conn_del+0x142/0x360 net/bluetooth/sco.c:206
hci_disconn_cfm include/net/bluetooth/hci_core.h:1520 [inline]
hci_conn_hash_flush+0x107/0x220 net/bluetooth/hci_conn.c:1622
hci_dev_do_close+0x991/0x1030 net/bluetooth/hci_core.c:1795
hci_unregister_dev+0x2d7/0x580 net/bluetooth/hci_core.c:4044
vhci_release+0x73/0xc0 drivers/bluetooth/hci_vhci.c:345
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f51050b1629
Code: Unable to access opcode bytes at RIP 0x7f51050b15ff.
RSP: 002b:00007ffe60ff59f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f5105146f15 RCX: 00007f51050b1629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f5105146ef0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe60ff6cb0
R13: 00007f5105146ef0 R14: 000055555bad94e8 R15: 00007ffe60ff7d80
general protection fault, probably for non-canonical address 0xdffffc00000000ba: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000005d0-0x00000000000005d7]
CPU: 0 PID: 7333 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1846 [inline]
RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1880
Code: ff df 80 3c 08 00 74 08 48 89 df e8 0f 2e ec fd 41 be d0 05 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 e7 2d ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc90003eef920 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff88806162fc88 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff1100c2c5f99 R08: ffffffff8d89dc2f R09: 1ffffffff1b13b85
R10: dffffc0000000000 R11: fffffbfff1b13b86 R12: ffff88802549d910
R13: ffff88806162fcc8 R14: 00000000000005d0 R15: ffff88802a193b80
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32e20ff8 CR3: 000000001f4c9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
bio_associate_blkg+0x23a/0x340 block/blk-cgroup.c:1908
lbmStartIO+0x204/0x4c0 fs/jfs/jfs_logmgr.c:2130
lbmWrite+0x361/0x480 fs/jfs/jfs_logmgr.c:2079
lmGCwrite fs/jfs/jfs_logmgr.c:-1 [inline]
jfs_flush_journal+0x537/0xec0 fs/jfs/jfs_logmgr.c:1556
jfs_umount+0xf8/0x360 fs/jfs/jfs_umount.c:58
jfs_put_super+0x88/0x190 fs/jfs/super.c:194
generic_shutdown_super+0x130/0x300 fs/super.c:475
kill_block_super+0x7c/0xe0 fs/super.c:1427
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f51050b1629
Code: Unable to access opcode bytes at RIP 0x7f51050b15ff.
RSP: 002b:00007ffe60ff59f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f5105146f15 RCX: 00007f51050b1629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f5105146ef0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe60ff6cb0
R13: 00007f5105146ef0 R14: 000055555bad94e8 R15: 00007ffe60ff7d80
Modules linked in:
---[ end trace 714437d697a8c243 ]---
RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1846 [inline]
RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1880
Code: ff df 80 3c 08 00 74 08 48 89 df e8 0f 2e ec fd 41 be d0 05 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 e7 2d ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc90003eef920 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff88806162fc88 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff1100c2c5f99 R08: ffffffff8d89dc2f R09: 1ffffffff1b13b85
R10: dffffc0000000000 R11: fffffbfff1b13b86 R12: ffff88802549d910
R13: ffff88806162fcc8 R14: 00000000000005d0 R15: ffff88802a193b80
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000006860a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: ff lcall (bad)
1: df 80 3c 08 00 74 filds 0x7400083c(%rax)
7: 08 48 89 or %cl,-0x77(%rax)
a: df e8 fucomip %st(0),%st
c: 0f 2e ec ucomiss %xmm4,%xmm5
f: fd std
10: 41 be d0 05 00 00 mov $0x5d0,%r14d
16: 4c 03 33 add (%rbx),%r14
19: 4c 89 f0 mov %r14,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 f7 mov %r14,%rdi
33: e8 e7 2d ec fd call 0xfdec2e1f
38: bb 90 00 00 00 mov $0x90,%ebx
3d: 49 03 1e add (%r14),%rbx