loop7: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.1496/12086 is trying to acquire lock: ffff88807064c0b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x14e/0x1d0 fs/hfs/bfind.c:-1 but task is already holding lock: ffff888044e434f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_get_block+0x259/0xbe0 fs/hfs/extent.c:365 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747 hfs_extend_file+0xe7/0x1380 fs/hfs/extent.c:397 hfs_bmap_reserve+0x104/0x420 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 hfs_ext_write_extent+0x17b/0x200 fs/hfs/extent.c:144 hfs_write_inode+0xd8/0xa20 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1470 [inline] __writeback_single_inode+0x76c/0x1170 fs/fs-writeback.c:1687 writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x484/0xd40 fs/fs-writeback.c:2089 wb_check_background_flush fs/fs-writeback.c:2155 [inline] wb_do_writeback fs/fs-writeback.c:2243 [inline] wb_workfn+0xc1c/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (&tree->tree_lock#2/1){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747 hfs_find_init+0x14e/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_get_block+0x4f8/0xbe0 fs/hfs/extent.c:366 block_read_full_folio+0x405/0xf80 fs/buffer.c:2271 filemap_read_folio+0x164/0x7a0 mm/filemap.c:2490 do_read_cache_folio+0x29e/0x790 mm/filemap.c:3659 do_read_cache_page+0x32/0x230 mm/filemap.c:3701 read_mapping_page include/linux/pagemap.h:793 [inline] hfs_btree_open+0x568/0x10b0 fs/hfs/btree.c:78 hfs_mdb_get+0x1474/0x2150 fs/hfs/mdb.c:204 hfs_fill_super+0xeaf/0x14e0 fs/hfs/super.c:406 mount_bdev+0x28a/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x247/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); *** DEADLOCK *** 2 locks held by syz.7.1496/12086: #0: ffff888074fa40e0 (&type->s_umount_key#110/1){+.+.}-{3:3}, at: alloc_super+0x1fb/0x930 fs/super.c:228 #1: ffff888044e434f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_get_block+0x259/0xbe0 fs/hfs/extent.c:365 stack backtrace: CPU: 1 PID: 12086 Comm: syz.7.1496 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747 hfs_find_init+0x14e/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_get_block+0x4f8/0xbe0 fs/hfs/extent.c:366 block_read_full_folio+0x405/0xf80 fs/buffer.c:2271 filemap_read_folio+0x164/0x7a0 mm/filemap.c:2490 do_read_cache_folio+0x29e/0x790 mm/filemap.c:3659 do_read_cache_page+0x32/0x230 mm/filemap.c:3701 read_mapping_page include/linux/pagemap.h:793 [inline] hfs_btree_open+0x568/0x10b0 fs/hfs/btree.c:78 hfs_mdb_get+0x1474/0x2150 fs/hfs/mdb.c:204 hfs_fill_super+0xeaf/0x14e0 fs/hfs/super.c:406 mount_bdev+0x28a/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x247/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb894f9e0ca Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007fb895e76e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fb895e76ee0 RCX: 00007fb894f9e0ca RDX: 0000200000000080 RSI: 0000200000000100 RDI: 00007fb895e76ea0 RBP: 0000200000000080 R08: 00007fb895e76ee0 R09: 0000000000204002 R10: 0000000000204002 R11: 0000000000000246 R12: 0000200000000100 R13: 00007fb895e76ea0 R14: 0000000000000351 R15: 0000200000000b40 hfs: unable to open catalog tree hfs: can't find a HFS filesystem on dev loop7