============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.1.76/7135 is trying to acquire lock: ffff0000d47a80f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xd4/0x10e4 fs/hfs/extent.c:397 but task is already holding lock: ffff0000d47a8778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xd4/0x10e4 fs/hfs/extent.c:397 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&HFS_I(tree->inode)->extents_lock); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz.1.76/7135: #0: ffff0000c77fe420 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:508 #1: ffff0000d47a8fa0 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff0000d47a8fa0 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: filename_create+0x1ac/0x32c fs/namei.c:4226 #2: ffff0000cb89c0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfs_find_init+0x168/0x28c fs/hfs/bfind.c:-1 #3: ffff0000d47a8778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xd4/0x10e4 fs/hfs/extent.c:397 #4: ffff0000cb89e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x168/0x28c fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 7135 Comm: syz.1.76 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_deadlock_bug+0x2e8/0x2f0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x2940/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 hfs_extend_file+0xd4/0x10e4 fs/hfs/extent.c:397 hfs_bmap_reserve+0xd4/0x3e0 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x19c/0x488 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x84/0x750 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x258/0x10e4 fs/hfs/extent.c:401 hfs_bmap_reserve+0xd4/0x3e0 fs/hfs/btree.c:269 hfs_cat_create+0x1a4/0x65c fs/hfs/catalog.c:104 hfs_create+0x6c/0xe0 fs/hfs/dir.c:202 vfs_create+0x21c/0x368 fs/namei.c:3493 do_mknodat+0x39c/0x4a8 fs/namei.c:4372 __do_sys_mknodat fs/namei.c:4400 [inline] __se_sys_mknodat fs/namei.c:4397 [inline] __arm64_sys_mknodat+0xac/0xc8 fs/namei.c:4397 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596