loop8: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.8.21097/22761 is trying to acquire lock: ffff88805415a320 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 but task is already holding lock: ffff88807f0ee0a8 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 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}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:206 [inline] hfs_get_block+0x4fd/0xbf0 fs/hfs/extent.c:372 block_read_full_folio+0x2db/0x8c0 fs/buffer.c:2310 filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2551 do_read_cache_folio+0x354/0x590 mm/filemap.c:4184 do_read_cache_page mm/filemap.c:4250 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4259 read_mapping_page include/linux/pagemap.h:969 [inline] __hfs_bnode_create+0x4a5/0x960 fs/hfs/bnode.c:346 hfs_bnode_find+0x209/0xcd0 fs/hfs/bnode.c:391 hfs_btree_open+0x1428/0x1f50 fs/hfs/btree.c:275 hfs_mdb_get+0x1552/0x2130 fs/hfs/mdb.c:280 hfs_fill_super+0x482/0x7c0 fs/hfs/super.c:352 get_tree_bdev_flags+0x436/0x500 fs/super.c:2104 vfs_get_tree+0x92/0x2a0 fs/super.c:2164 fc_mount fs/namespace.c:1282 [inline] do_new_mount_fc fs/namespace.c:4000 [inline] do_new_mount+0x325/0xb00 fs/namespace.c:4076 do_mount fs/namespace.c:4440 [inline] __do_sys_mount fs/namespace.c:4655 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4632 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x171/0x540 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402 __hfs_ext_write_extent+0x200/0x620 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:180 hfs_ext_read_extent fs/hfs/extent.c:208 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:407 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:359 __block_write_begin_int+0x6c1/0x1930 fs/buffer.c:2032 block_write_begin fs/buffer.c:2146 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2508 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 generic_perform_write+0x359/0x9e0 mm/filemap.c:4389 generic_file_write_iter+0xae/0x330 mm/filemap.c:4532 new_sync_write fs/read_write.c:575 [inline] vfs_write+0x612/0xba0 fs/read_write.c:667 ksys_write+0x150/0x270 fs/read_write.c:1016 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x171/0x540 arch/x86/entry/syscall_64.c:89 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 *** locks held by syz.8.21097/22761: 5, on CPU#0: #0: ffff8880346eed30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1413 #1: ffff88802db78478 (sb_writers#26){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2765 [inline] #1: ffff88802db78478 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:663 #2: ffff888054159940 (&sb->s_type->i_mutex_key#56){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #2: ffff888054159940 (&sb->s_type->i_mutex_key#56){+.+.}-{4:4}, at: generic_file_write_iter+0x82/0x330 mm/filemap.c:4529 #3: ffff8880541597a0 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 #4: ffff88807f0ee0a8 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 22761 Comm: syz.8.21097 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402 __hfs_ext_write_extent+0x200/0x620 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:180 hfs_ext_read_extent fs/hfs/extent.c:208 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:407 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:359 __block_write_begin_int+0x6c1/0x1930 fs/buffer.c:2032 block_write_begin fs/buffer.c:2146 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2508 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 generic_perform_write+0x359/0x9e0 mm/filemap.c:4389 generic_file_write_iter+0xae/0x330 mm/filemap.c:4532 new_sync_write fs/read_write.c:575 [inline] vfs_write+0x612/0xba0 fs/read_write.c:667 ksys_write+0x150/0x270 fs/read_write.c:1016 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x171/0x540 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x00007fddf13a8f19 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fddf22ce028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fddf1625fa0 RCX: 00007fddf13a8f19 RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007fddf1437f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fddf1626038 R14: 00007fddf1625fa0 R15: 00007ffee3e07ac8