loop4: detected capacity change from 0 to 64
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.164/6981 is trying to acquire lock:
ffff8880633fa0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
but task is already holding lock:
ffff8880633fa0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&tree->tree_lock/1);
lock(&tree->tree_lock/1);
*** DEADLOCK ***
May be due to missing lock nesting notation
5 locks held by syz.4.164/6981:
#0: ffff8880633f8480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805b1c6140 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline]
#1: ffff88805b1c6140 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
#2: ffff88805b1c5f68 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397
#3: ffff8880633fa0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
#4: ffff88805b1c49a8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397
stack backtrace:
CPU: 0 UID: 0 PID: 6981 Comm: syz.4.164 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain kernel/locking/lockdep.c:3895 [inline]
__lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_extend_file+0x2f6/0x1540 fs/hfs/extent.c:401
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
__hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
hfs_extend_file+0x31e/0x1540 fs/hfs/extent.c:401
hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin fs/buffer.c:2256 [inline]
cont_write_begin+0x78c/0xb50 fs/buffer.c:2594
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
cont_expand_zero fs/buffer.c:2522 [inline]
cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
hfs_file_truncate+0x19c/0xb30 fs/hfs/extent.c:495
hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:666
notify_change+0xc18/0xf60 fs/attr.c:546
do_truncate+0x1a4/0x220 fs/open.c:68
vfs_truncate+0x493/0x520 fs/open.c:118
do_sys_truncate+0xdb/0x190 fs/open.c:141
__do_sys_truncate fs/open.c:153 [inline]
__se_sys_truncate fs/open.c:151 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:151
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f667273f749
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:00007f667099e038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f6672995fa0 RCX: 00007f667273f749
RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900
RBP: 00007f66727c3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6672996038 R14: 00007f6672995fa0 R15: 00007ffe39230948
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: kernel/locking/rtmutex.c:1674 at 0x0, CPU#0: syz.4.164/6981
Modules linked in:
CPU: 0 UID: 0 PID: 6981 Comm: syz.4.164 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674
Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 86 00 00 00 48 89 f7 e8 66 3b 01 00 48 8d 3d cf eb 08 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 a0 b1 91 4c
RSP: 0018:ffffc90003cd6c90 EFLAGS: 00010286
RAX: 0000000080000000 RBX: ffffc90003cd6d20 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b3f4bc0 RDI: ffffffff8ede2bf0
RBP: ffffc90003cd6e28 R08: ffffffff8edb0977 R09: 1ffffffff1db612e
R10: dffffc0000000000 R11: fffffbfff1db612f R12: 1ffff9200079ada0
R13: ffffffff8ad53b09 R14: ffff8880633fa048 R15: dffffc0000000000
FS: 00007f667099e6c0(0000) GS:ffff888126d06000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000004e5d8000 CR4: 00000000003526f0
Call Trace:
__rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x666/0x6b0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_extend_file+0x2f6/0x1540 fs/hfs/extent.c:401
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
__hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
hfs_extend_file+0x31e/0x1540 fs/hfs/extent.c:401
hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin fs/buffer.c:2256 [inline]
cont_write_begin+0x78c/0xb50 fs/buffer.c:2594
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
cont_expand_zero fs/buffer.c:2522 [inline]
cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
hfs_file_truncate+0x19c/0xb30 fs/hfs/extent.c:495
hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:666
notify_change+0xc18/0xf60 fs/attr.c:546
do_truncate+0x1a4/0x220 fs/open.c:68
vfs_truncate+0x493/0x520 fs/open.c:118
do_sys_truncate+0xdb/0x190 fs/open.c:141
__do_sys_truncate fs/open.c:153 [inline]
__se_sys_truncate fs/open.c:151 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:151
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f667273f749
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:00007f667099e038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f6672995fa0 RCX: 00007f667273f749
RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900
RBP: 00007f66727c3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6672996038 R14: 00007f6672995fa0 R15: 00007ffe39230948
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 41 57 push %r15
b: 41 56 push %r14
d: 41 55 push %r13
f: 41 54 push %r12
11: 53 push %rbx
12: 83 ff dd cmp $0xffffffdd,%edi
15: 0f 85 86 00 00 00 jne 0xa1
1b: 48 89 f7 mov %rsi,%rdi
1e: e8 66 3b 01 00 call 0x13b89
23: 48 8d 3d cf eb 08 04 lea 0x408ebcf(%rip),%rdi # 0x408ebf9
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36
36: 65 48 8b 1c 25 08 a0 mov %gs:0xffffffff91b1a008,%rbx
3d: b1 91
3f: 4c rex.WR