loop0: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.0.15884/12147 is trying to acquire lock: ffff888054d780f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397 but task is already holding lock: ffff88804d1880b0 (&tree->tree_lock#2/1){+.+.}-{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#2/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_get_block+0x556/0xc50 fs/hfs/extent.c:366 block_read_full_folio+0x29f/0x830 fs/buffer.c:2421 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2496 do_read_cache_folio+0x358/0x590 mm/filemap.c:4096 do_read_cache_page mm/filemap.c:4162 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4171 read_mapping_page include/linux/pagemap.h:1022 [inline] __hfs_bnode_create+0x4b9/0x980 fs/hfs/bnode.c:388 hfs_bnode_find+0x211/0xd40 fs/hfs/bnode.c:433 hfs_brec_find+0x17b/0x510 fs/hfs/bfind.c:135 hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:174 hfs_cat_find_brec+0x177/0x3f0 fs/hfs/catalog.c:194 hfs_fill_super+0x4ff/0x750 fs/hfs/super.c:354 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 hfs_extend_file+0xf2/0x15e0 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+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:2146 block_write_begin fs/buffer.c:2257 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2595 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2523 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2585 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 hfs_file_truncate+0x1cf/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:666 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1c2/0x250 fs/open.c:68 do_ftruncate+0x4db/0x5c0 fs/open.c:196 do_sys_ftruncate fs/open.c:208 [inline] __do_sys_ftruncate fs/open.c:213 [inline] __se_sys_ftruncate fs/open.c:211 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:211 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 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#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.0.15884/12147: #0: ffff88804b25c420 (sb_writers#31){.+.+}-{0:0}, at: class_super_write_constructor include/linux/fs/super.h:128 [inline] #0: ffff88804b25c420 (sb_writers#31){.+.+}-{0:0}, at: do_ftruncate+0x47c/0x5c0 fs/open.c:195 #1: ffff888054d7a9a0 (&sb->s_type->i_mutex_key#40){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline] #1: ffff888054d7a9a0 (&sb->s_type->i_mutex_key#40){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff888054d7a7f8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397 #3: ffff88804d1880b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 12147 Comm: syz.0.15884 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 hfs_extend_file+0xf2/0x15e0 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+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:2146 block_write_begin fs/buffer.c:2257 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2595 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2523 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2585 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 hfs_file_truncate+0x1cf/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:666 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1c2/0x250 fs/open.c:68 do_ftruncate+0x4db/0x5c0 fs/open.c:196 do_sys_ftruncate fs/open.c:208 [inline] __do_sys_ftruncate fs/open.c:213 [inline] __se_sys_ftruncate fs/open.c:211 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:211 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f105419aeb9 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:00007f1054fa7028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007f1054415fa0 RCX: 00007f105419aeb9 RDX: 0000000000000000 RSI: 0000000002000009 RDI: 0000000000000004 RBP: 00007f1054208c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1054416038 R14: 00007f1054415fa0 R15: 00007ffc00d25bd8