============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.2.359/5605 is trying to acquire lock: ffff0000f449a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1 but task is already holding lock: ffff0000f449a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock/1); lock(&tree->tree_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by syz.2.359/5605: #0: ffff0000cbc92868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000f3c82460 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff0000f4cd1518 (&sb->s_type->i_mutex_key#32){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline] #2: ffff0000f4cd1518 (&sb->s_type->i_mutex_key#32){+.+.}-{3:3}, at: generic_file_write_iter+0x84/0x2b0 mm/filemap.c:3986 #3: ffff0000f4cd1368 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x100c fs/hfs/extent.c:397 #4: ffff0000f449a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1 #5: ffff0000f4cd00a8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x100c fs/hfs/extent.c:397 stack backtrace: CPU: 0 PID: 5605 Comm: syz.2.359 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_deadlock_bug+0x454/0x5c8 kernel/locking/lockdep.c:3040 check_deadlock kernel/locking/lockdep.c:3090 [inline] validate_chain kernel/locking/lockdep.c:3884 [inline] __lock_acquire+0x6020/0x7280 kernel/locking/lockdep.c:5171 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x25c/0x100c fs/hfs/extent.c:401 hfs_bmap_reserve+0xdc/0x3a8 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x19c/0x480 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x84/0x76c fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x29c/0x100c fs/hfs/extent.c:401 hfs_get_block+0x300/0xa14 fs/hfs/extent.c:353 __block_write_begin_int+0x3d8/0x13c0 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin fs/buffer.c:2102 [inline] cont_write_begin+0x5b4/0x820 fs/buffer.c:2456 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:59 generic_perform_write+0x240/0x508 mm/filemap.c:3862 __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2271 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585