============================================ WARNING: possible recursive locking detected 6.1.105-syzkaller #0 Not tainted -------------------------------------------- syz.2.129/4762 is trying to acquire lock: ffff0000c9a1e0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 but task is already holding lock: ffff0000c9a1e0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 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 5 locks held by syz.2.129/4762: #0: ffff0000da3e4460 (sb_writers#19){.+.+}-{0:0}, at: do_sys_ftruncate+0x214/0x31c fs/open.c:190 #1: ffff0000dda502a8 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000dda502a8 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: do_truncate+0x1ac/0x28c fs/open.c:63 #2: ffff0000dda500f8 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 #3: ffff0000c9a1e0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 #4: ffff0000d9c680f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 stack backtrace: CPU: 0 PID: 4762 Comm: syz.2.129 Not tainted 6.1.105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 __lock_acquire+0x6310/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 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+0x148/0x1c8 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x270/0x1130 fs/hfs/extent.c:401 hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x84/0x754 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x29c/0x1130 fs/hfs/extent.c:401 hfs_get_block+0x3b8/0x9e0 fs/hfs/extent.c:353 __block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin fs/buffer.c:2102 [inline] cont_write_begin+0x5c0/0x7d8 fs/buffer.c:2456 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ac/0x7d8 fs/buffer.c:2446 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58 hfs_file_truncate+0x1a4/0xeb0 fs/hfs/extent.c:494 hfs_inode_setattr+0x3a8/0x5c8 fs/hfs/inode.c:659 notify_change+0xb58/0xe1c fs/attr.c:499 do_truncate+0x1c0/0x28c fs/open.c:65 do_sys_ftruncate+0x288/0x31c fs/open.c:193 __do_sys_ftruncate fs/open.c:204 [inline] __se_sys_ftruncate fs/open.c:202 [inline] __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x168 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