====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.5660/30477 is trying to acquire lock: ffff88807981ef78 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa5/0xcd0 fs/hfs/extent.c:397 but task is already holding lock: ffff888024f720b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x19c/0x310 fs/hfs/bfind.c:36 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+0x1aa/0x1b10 kernel/locking/mutex.c:776 hfs_find_init+0x19c/0x310 fs/hfs/bfind.c:36 hfs_ext_read_extent+0x19b/0x9e0 fs/hfs/extent.c:200 hfs_extend_file+0x519/0xcd0 fs/hfs/extent.c:401 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 hfs_cat_create+0x32c/0x960 fs/hfs/catalog.c:104 hfs_create+0x6b/0xf0 fs/hfs/dir.c:202 lookup_open.isra.0+0x12dc/0x1780 fs/namei.c:4440 open_last_lookups fs/namei.c:4540 [inline] path_openat+0xa95/0x3140 fs/namei.c:4784 do_filp_open+0x20b/0x470 fs/namei.c:4814 do_sys_openat2+0x11f/0x280 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_creat fs/open.c:1514 [inline] __se_sys_creat fs/open.c:1508 [inline] __x64_sys_creat+0xcc/0x120 fs/open.c:1508 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/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+0x1542/0x22f0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1aa/0x1b10 kernel/locking/mutex.c:776 hfs_extend_file+0xa5/0xcd0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 __hfs_ext_cache_extent fs/hfs/extent.c:174 [inline] hfs_ext_read_extent+0x807/0x9e0 fs/hfs/extent.c:202 hfs_extend_file+0x519/0xcd0 fs/hfs/extent.c:401 hfs_get_block+0x17f/0x830 fs/hfs/extent.c:353 __block_write_begin_int+0x4f4/0x16d0 fs/buffer.c:2145 block_write_begin+0x9a/0x1d0 fs/buffer.c:2256 cont_write_begin+0x61a/0x950 fs/buffer.c:2594 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x34f/0x950 fs/buffer.c:2584 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 hfs_file_truncate+0xd08/0x1120 fs/hfs/extent.c:495 hfs_inode_setattr+0x497/0x5e0 fs/hfs/inode.c:665 notify_change+0x6d2/0x1290 fs/attr.c:546 do_truncate+0x1d7/0x230 fs/open.c:68 do_ftruncate+0x59e/0x920 fs/open.c:195 do_sys_ftruncate+0x61/0xb0 fs/open.c:207 __do_sys_ftruncate fs/open.c:212 [inline] __se_sys_ftruncate fs/open.c:210 [inline] __x64_sys_ftruncate+0x58/0x80 fs/open.c:210 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/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.3.5660/30477: #0: ffff88805164a420 (sb_writers#28){.+.+}-{0:0}, at: do_sys_ftruncate+0x61/0xb0 fs/open.c:207 #1: ffff888068c9d720 (&sb->s_type->i_mutex_key#46){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline] #1: ffff888068c9d720 (&sb->s_type->i_mutex_key#46){+.+.}-{4:4}, at: do_truncate+0x146/0x230 fs/open.c:63 #2: ffff888068c9d578 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa5/0xcd0 fs/hfs/extent.c:397 #3: ffff888024f720b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x19c/0x310 fs/hfs/bfind.c:36 stack backtrace: CPU: 1 UID: 0 PID: 30477 Comm: syz.3.5660 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x2db/0x410 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 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+0x1542/0x22f0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1aa/0x1b10 kernel/locking/mutex.c:776 hfs_extend_file+0xa5/0xcd0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 __hfs_ext_cache_extent fs/hfs/extent.c:174 [inline] hfs_ext_read_extent+0x807/0x9e0 fs/hfs/extent.c:202 hfs_extend_file+0x519/0xcd0 fs/hfs/extent.c:401 hfs_get_block+0x17f/0x830 fs/hfs/extent.c:353 __block_write_begin_int+0x4f4/0x16d0 fs/buffer.c:2145 block_write_begin+0x9a/0x1d0 fs/buffer.c:2256 cont_write_begin+0x61a/0x950 fs/buffer.c:2594 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x34f/0x950 fs/buffer.c:2584 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 hfs_file_truncate+0xd08/0x1120 fs/hfs/extent.c:495 hfs_inode_setattr+0x497/0x5e0 fs/hfs/inode.c:665 notify_change+0x6d2/0x1290 fs/attr.c:546 do_truncate+0x1d7/0x230 fs/open.c:68 do_ftruncate+0x59e/0x920 fs/open.c:195 do_sys_ftruncate+0x61/0xb0 fs/open.c:207 __do_sys_ftruncate fs/open.c:212 [inline] __se_sys_ftruncate fs/open.c:210 [inline] __x64_sys_ftruncate+0x58/0x80 fs/open.c:210 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f395858f749 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:00007f395949d038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007f39587e6270 RCX: 00007f395858f749 RDX: 0000000000000000 RSI: 0000000000008979 RDI: 0000000000000004 RBP: 00007f3958613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f39587e6308 R14: 00007f39587e6270 R15: 00007ffd4b1469e8