============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.127/6586 is trying to acquire lock:
ffff8880665aa0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
but task is already holding lock:
ffff8880665aa0a0 (&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
6 locks held by syz.4.127/6586:
#0: ffff88803f672928 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261
#1: ffff888032834480 (sb_writers#14){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#1: ffff888032834480 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#2: ffff8880403aefc0 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#2: ffff8880403aefc0 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: generic_file_write_iter+0x11f/0x690 mm/filemap.c:4454
#3: ffff8880403aede8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397
#4: ffff8880665aa0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
#5: ffff8880402b0fa8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397
stack backtrace:
CPU: 1 UID: 0 PID: 6586 Comm: syz.4.127 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 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+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0xf0/0x2e0 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+0x35c/0x15e0 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+0x39b/0x15e0 fs/hfs/extent.c:401
hfs_get_block+0x412/0xc50 fs/hfs/extent.c:353
__block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
block_write_begin fs/buffer.c:2253 [inline]
cont_write_begin+0x737/0xae0 fs/buffer.c:2591
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
generic_perform_write+0x2af/0x8b0 mm/filemap.c:4314
generic_file_write_iter+0x14b/0x690 mm/filemap.c:4457
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4fb3c6c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4fb1ebe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4fb3ee5fa0 RCX: 00007f4fb3c6c629
RDX: 00000000ffffff20 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f4fb3d02b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4fb3ee6038 R14: 00007f4fb3ee5fa0 R15: 00007fff35a95668
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: kernel/locking/rtmutex.c:1674 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674, CPU#1: syz.4.127/6586
Modules linked in:
CPU: 1 UID: 0 PID: 6586 Comm: syz.4.127 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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 81 00 00 00 48 89 f7 e8 56 3a 01 00 48 8d 3d bf 4a 49 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1d 33 c3 29 07 4c 8d
RSP: 0018:ffffc9000d666d70 EFLAGS: 00010286
RAX: 0000000080000000 RBX: ffffc9000d666e00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8ba64460 RDI: ffffffff8f6d5780
RBP: ffffc9000d666f08 R08: ffffffff8f6a25b7 R09: 1ffffffff1ed44b6
R10: dffffc0000000000 R11: fffffbfff1ed44b7 R12: 1ffff92001accdbc
R13: ffffffff8b2406dd R14: ffff8880665aa048 R15: dffffc0000000000
FS: 00007f4fb1ebe6c0(0000) GS:ffff888126443000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000938000 CR3: 0000000054cd8000 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+0x760/0x7b0 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+0x168/0x1d0 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+0x35c/0x15e0 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+0x39b/0x15e0 fs/hfs/extent.c:401
hfs_get_block+0x412/0xc50 fs/hfs/extent.c:353
__block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
block_write_begin fs/buffer.c:2253 [inline]
cont_write_begin+0x737/0xae0 fs/buffer.c:2591
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53
generic_perform_write+0x2af/0x8b0 mm/filemap.c:4314
generic_file_write_iter+0x14b/0x690 mm/filemap.c:4457
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4fb3c6c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4fb1ebe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4fb3ee5fa0 RCX: 00007f4fb3c6c629
RDX: 00000000ffffff20 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f4fb3d02b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4fb3ee6038 R14: 00007f4fb3ee5fa0 R15: 00007fff35a95668
----------------
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 81 00 00 00 jne 0x9c
1b: 48 89 f7 mov %rsi,%rdi
1e: e8 56 3a 01 00 call 0x13a79
23: 48 8d 3d bf 4a 49 04 lea 0x4494abf(%rip),%rdi # 0x4494ae9
* 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 1d 33 c3 29 mov %gs:0x729c333(%rip),%rbx # 0x729c371
3d: 07
3e: 4c rex.WR
3f: 8d .byte 0x8d