====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.7.16226/12381 is trying to acquire lock: ffff8880507264f0 (&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: ffff88805125e0a8 (&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/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 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:2317 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x358/0x590 mm/filemap.c:4107 do_read_cache_page mm/filemap.c:4173 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4182 read_mapping_page include/linux/pagemap.h:1011 [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:357 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:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/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+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 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:2042 block_write_begin fs/buffer.c:2153 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2491 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2419 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2481 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:667 notify_change+0xc1a/0xf40 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b4/0x540 fs/open.c:118 ksys_truncate+0xf3/0x1c0 fs/open.c:142 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/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.7.16226/12381: #0: ffff888088ab2410 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888050724d90 (&sb->s_type->i_mutex_key#53){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1034 [inline] #1: ffff888050724d90 (&sb->s_type->i_mutex_key#53){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff888050724bf0 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397 #3: ffff88805125e0a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 12381 Comm: syz.7.16226 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 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:2042 block_write_begin fs/buffer.c:2153 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2491 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2419 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2481 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:667 notify_change+0xc1a/0xf40 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b4/0x540 fs/open.c:118 ksys_truncate+0xf3/0x1c0 fs/open.c:142 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa6c0f9cdd9 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:00007fa6c1d9b028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007fa6c1215fa0 RCX: 00007fa6c0f9cdd9 RDX: 0000000000000000 RSI: 0000000002fffffd RDI: 0000200000000940 RBP: 00007fa6c1032d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa6c1216038 R14: 00007fa6c1215fa0 R15: 00007ffd0071c268