====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.8.1079/12137 is trying to acquire lock: ffff88804cd06260 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 but task is already holding lock: ffff88807d21e0a8 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/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:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x35f/0x1680 fs/hfs/extent.c:401 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:269 hfs_cat_create+0x221/0x810 fs/hfs/catalog.c:104 hfs_mkdir+0x79/0xe0 fs/hfs/dir.c:226 vfs_mkdir+0x406/0x620 fs/namei.c:5276 filename_mkdirat+0x285/0x510 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0x1520/0x2cf0 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+0x19d/0x1550 kernel/locking/mutex.c:821 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x3a0/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbe0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123 block_write_begin fs/buffer.c:2234 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2596 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 cont_expand_zero fs/buffer.c:2524 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2586 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4358 generic_file_write_iter+0xae/0x330 mm/filemap.c:4501 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_pwrite64 fs/read_write.c:794 [inline] __do_sys_pwrite64 fs/read_write.c:802 [inline] __se_sys_pwrite64 fs/read_write.c:799 [inline] __x64_sys_pwrite64+0x196/0x220 fs/read_write.c:799 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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.8.1079/12137: #0: ffff88807b97a450 (sb_writers#29){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88807b97a450 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #1: ffff88804cd052c0 (&sb->s_type->i_mutex_key#48){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff88804cd052c0 (&sb->s_type->i_mutex_key#48){+.+.}-{4:4}, at: generic_file_write_iter+0x82/0x330 mm/filemap.c:4498 #2: ffff88804cd05120 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 #3: ffff88807d21e0a8 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 12137 Comm: syz.8.1079 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 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+0x1520/0x2cf0 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+0x19d/0x1550 kernel/locking/mutex.c:821 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x3a0/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbe0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123 block_write_begin fs/buffer.c:2234 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2596 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 cont_expand_zero fs/buffer.c:2524 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2586 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4358 generic_file_write_iter+0xae/0x330 mm/filemap.c:4501 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_pwrite64 fs/read_write.c:794 [inline] __do_sys_pwrite64 fs/read_write.c:802 [inline] __se_sys_pwrite64 fs/read_write.c:799 [inline] __x64_sys_pwrite64+0x196/0x220 fs/read_write.c:799 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f58b079de99 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:00007f58b1690028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f58b0a25fa0 RCX: 00007f58b079de99 RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000004 RBP: 00007f58b0833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f58b0a26038 R14: 00007f58b0a25fa0 R15: 00007fff2e6131b8