loop4: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 Not tainted ------------------------------------------------------ syz.4.3848/21088 is trying to acquire lock: ffff88805587a7f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397 but task is already holding lock: ffff8880227d20b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x165/0x1e0 fs/hfs/bfind.c:-1 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfs_find_init+0x165/0x1e0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_get_block+0x51b/0xbd0 fs/hfs/extent.c:366 block_read_full_folio+0x29c/0x830 fs/buffer.c:2427 filemap_read_folio+0x114/0x380 mm/filemap.c:2401 do_read_cache_folio+0x354/0x590 mm/filemap.c:3885 do_read_cache_page mm/filemap.c:3951 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:3960 read_mapping_page include/linux/pagemap.h:989 [inline] __hfs_bnode_create+0x4a8/0x7f0 fs/hfs/bnode.c:296 hfs_bnode_find+0x224/0xcc0 fs/hfs/bnode.c:341 hfs_brec_find+0x159/0x500 fs/hfs/bfind.c:126 hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:165 hfs_cat_find_brec+0x15c/0x3f0 fs/hfs/catalog.c:194 hfs_fill_super+0x426/0x640 fs/hfs/super.c:350 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 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:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x316/0x1230 fs/hfs/extent.c:401 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2601 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2528 [inline] cont_write_begin+0x2fa/0xb50 fs/buffer.c:2591 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52 hfs_file_truncate+0x190/0x9c0 fs/hfs/extent.c:494 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:654 notify_change+0xb33/0xe40 fs/attr.c:552 do_truncate+0x19a/0x220 fs/open.c:65 vfs_truncate+0x493/0x520 fs/open.c:115 do_sys_truncate+0xdb/0x190 fs/open.c:138 __do_sys_truncate fs/open.c:150 [inline] __se_sys_truncate fs/open.c:148 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:148 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 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.4.3848/21088: #0: ffff888046bdc420 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805587a320 (&sb->s_type->i_mutex_key#39){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88805587a320 (&sb->s_type->i_mutex_key#39){+.+.}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63 #2: ffff88805587a178 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397 #3: ffff8880227d20b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x165/0x1e0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 21088 Comm: syz.4.3848 Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x316/0x1230 fs/hfs/extent.c:401 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2601 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2528 [inline] cont_write_begin+0x2fa/0xb50 fs/buffer.c:2591 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52 hfs_file_truncate+0x190/0x9c0 fs/hfs/extent.c:494 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:654 notify_change+0xb33/0xe40 fs/attr.c:552 do_truncate+0x19a/0x220 fs/open.c:65 vfs_truncate+0x493/0x520 fs/open.c:115 do_sys_truncate+0xdb/0x190 fs/open.c:138 __do_sys_truncate fs/open.c:150 [inline] __se_sys_truncate fs/open.c:148 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:148 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f60c198e969 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:00007f60c2787038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f60c1bb5fa0 RCX: 00007f60c198e969 RDX: 0000000000000000 RSI: 0000000001001bfc RDI: 0000200000000040 RBP: 00007f60c1a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f60c1bb5fa0 R15: 00007ffda251ca88