loop0: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.80/6494 is trying to acquire lock: ffff88802f7c5f68 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397 but task is already holding lock: ffff88803192e0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock/1){+.+.}-{4:4}: __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_cat_create+0x1c5/0x770 fs/hfs/catalog.c:104 hfs_create+0x66/0xe0 fs/hfs/dir.c:202 vfs_create+0x3b2/0x410 fs/namei.c:4132 do_mknodat+0x3ee/0x620 fs/namei.c:5039 __do_sys_mknodat fs/namei.c:5071 [inline] __se_sys_mknodat fs/namei.c:5068 [inline] __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:5068 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 -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 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_extend_file+0xda/0x1540 fs/hfs/extent.c:397 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 do_ftruncate+0x4b1/0x570 fs/open.c:195 do_sys_ftruncate fs/open.c:207 [inline] __do_sys_ftruncate fs/open.c:212 [inline] __se_sys_ftruncate fs/open.c:210 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:210 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.0.80/6494: #0: ffff88805f2f4480 (sb_writers#27){.+.+}-{0:0}, at: class_super_write_constructor include/linux/fs/super.h:128 [inline] #0: ffff88805f2f4480 (sb_writers#27){.+.+}-{0:0}, at: do_ftruncate+0x452/0x570 fs/open.c:194 #1: ffff88803ad68a40 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline] #1: ffff88803ad68a40 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63 #2: ffff88803ad68868 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397 #3: ffff88803192e0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 6494 Comm: syz.0.80 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_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 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_extend_file+0xda/0x1540 fs/hfs/extent.c:397 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 do_ftruncate+0x4b1/0x570 fs/open.c:195 do_sys_ftruncate fs/open.c:207 [inline] __do_sys_ftruncate fs/open.c:212 [inline] __se_sys_ftruncate fs/open.c:210 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:210 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: 0033:0x7f537075f749 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:00007f536e9be038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007f53709b5fa0 RCX: 00007f537075f749 RDX: 0000000000000000 RSI: 0000000002000009 RDI: 0000000000000004 RBP: 00007f53707e3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f53709b6038 R14: 00007f53709b5fa0 R15: 00007ffc699b72d8