loop0: detected capacity change from 0 to 64 ============================================ WARNING: possible recursive locking detected 6.7.0-rc5-syzkaller-gd5b235ec8eab #0 Not tainted -------------------------------------------- syz-executor386/6089 is trying to acquire lock: ffff0000dbd820b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 but task is already holding lock: ffff0000dbd820b0 (&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-executor386/6089: #0: ffff0000dbd80418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x240/0x910 fs/read_write.c:580 #1: ffff0000daa79628 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #1: ffff0000daa79628 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: generic_file_write_iter+0x88/0x2b4 mm/filemap.c:4036 #2: ffff0000daa79478 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 #3: ffff0000dbd820b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 #4: ffff0000daa780f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 stack backtrace: CPU: 1 PID: 6089 Comm: syz-executor386 Not tainted 6.7.0-rc5-syzkaller-gd5b235ec8eab #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 print_deadlock_bug+0x4e4/0x660 kernel/locking/lockdep.c:3012 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x5fe4/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5754 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 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+0x3f0/0x1504 fs/buffer.c:2119 __block_write_begin fs/buffer.c:2168 [inline] block_write_begin fs/buffer.c:2227 [inline] cont_write_begin+0x798/0xc38 fs/buffer.c:2582 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58 generic_perform_write+0x28c/0x588 mm/filemap.c:3918 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4013 generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:4039 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x610/0x910 fs/read_write.c:584 ksys_write+0x15c/0x26c 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:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595