loop0: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc7-syzkaller-g89be9a83ccf1 #0 Not tainted ------------------------------------------------------ syz.0.41/6660 is trying to acquire lock: ffff88801db2e8f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xd6/0x1220 fs/hfs/extent.c:397 but task is already holding lock: ffff88807555e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x161/0x1e0 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/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x17d/0xe30 kernel/locking/mutex.c:747 hfs_find_init+0x161/0x1e0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x2ea/0x1220 fs/hfs/extent.c:401 hfs_bmap_reserve+0x103/0x430 fs/hfs/btree.c:234 hfs_cat_create+0x1af/0x630 fs/hfs/catalog.c:104 hfs_create+0x62/0xd0 fs/hfs/dir.c:202 lookup_open fs/namei.c:3717 [inline] open_last_lookups fs/namei.c:3816 [inline] path_openat+0x14f0/0x3830 fs/namei.c:4052 do_filp_open+0x1f6/0x400 fs/namei.c:4082 do_sys_openat2+0x11d/0x1b0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x134/0x160 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x15bc/0x2df0 kernel/locking/lockdep.c:5240 lock_acquire+0x11c/0x350 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x17d/0xe30 kernel/locking/mutex.c:747 hfs_extend_file+0xd6/0x1220 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x430 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 hfs_ext_write_extent+0x15d/0x1e0 fs/hfs/extent.c:144 hfs_write_inode+0x8d/0x7d0 fs/hfs/inode.c:429 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6f1/0xfc0 fs/fs-writeback.c:1745 writeback_single_inode+0x1f3/0x6a0 fs/fs-writeback.c:1801 write_inode_now+0x154/0x1c0 fs/fs-writeback.c:2863 hfs_file_fsync+0xa0/0x140 fs/hfs/inode.c:676 generic_write_sync include/linux/fs.h:3031 [inline] generic_file_write_iter+0x30d/0x530 mm/filemap.c:4259 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x523/0xa80 fs/read_write.c:686 ksys_write+0x141/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.0.41/6660: #0: ffff88807fc4d278 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x243/0x310 fs/file.c:1217 #1: ffff888073998428 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline] #1: ffff888073998428 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x20d/0xa80 fs/read_write.c:682 #2: ffff888026e382a0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #2: ffff888026e382a0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: hfs_file_fsync+0x96/0x140 fs/hfs/inode.c:673 #3: ffff88807555e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x161/0x1e0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 6660 Comm: syz.0.41 Not tainted 6.16.0-rc7-syzkaller-g89be9a83ccf1 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x185/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ed/0x300 kernel/locking/lockdep.c:2046 check_noncircular+0x130/0x150 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x15bc/0x2df0 kernel/locking/lockdep.c:5240 lock_acquire+0x11c/0x350 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x17d/0xe30 kernel/locking/mutex.c:747 hfs_extend_file+0xd6/0x1220 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x430 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 hfs_ext_write_extent+0x15d/0x1e0 fs/hfs/extent.c:144 hfs_write_inode+0x8d/0x7d0 fs/hfs/inode.c:429 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6f1/0xfc0 fs/fs-writeback.c:1745 writeback_single_inode+0x1f3/0x6a0 fs/fs-writeback.c:1801 write_inode_now+0x154/0x1c0 fs/fs-writeback.c:2863 hfs_file_fsync+0xa0/0x140 fs/hfs/inode.c:676 generic_write_sync include/linux/fs.h:3031 [inline] generic_file_write_iter+0x30d/0x530 mm/filemap.c:4259 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x523/0xa80 fs/read_write.c:686 ksys_write+0x141/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7ff64c38e9a9 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:00007ff64d111038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff64c5b5fa0 RCX: 00007ff64c38e9a9 RDX: 0000000000001006 RSI: 0000200000000940 RDI: 0000000000000008 RBP: 00007ff64c410d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff64c5b5fa0 R15: 00007ffec7d1d7c8