syzbot

ntfs3(loop1): ino=21, "file1" fallocate(0x10) is not supported
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.865/13876 is trying to acquire lock:
ffff888037160430 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:601

but task is already holding lock:
ffff88803fb0dc10 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1222 [inline]
ffff88803fb0dc10 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_readdir+0x752/0xec0 fs/ntfs3/dir.c:499

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ni->ni_lock/5){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
       ni_lock fs/ntfs3/ntfs_fs.h:1222 [inline]
       attr_data_get_block+0x1bf/0x2a0 fs/ntfs3/attrib.c:976
       ntfs_iomap_begin+0x4f0/0xf10 fs/ntfs3/inode.c:771
       iomap_iter+0x5f5/0xf80 fs/iomap/iter.c:110
       iomap_readahead+0xa4a/0xe80 fs/iomap/buffered-io.c:721
       ntfs_readahead+0x193/0x210 fs/ntfs3/inode.c:673
       read_pages+0x193/0x5a0 mm/readahead.c:174
       page_cache_ra_unbounded+0x679/0x8f0 mm/readahead.c:315
       do_page_cache_ra mm/readahead.c:348 [inline]
       page_cache_ra_order+0x2c1/0x4a0 mm/readahead.c:558
       filemap_get_pages+0x493/0x1e80 mm/filemap.c:2704
       filemap_read+0x429/0x11e0 mm/filemap.c:2814
       do_iter_readv_writev+0x624/0x8d0 fs/read_write.c:-1
       vfs_readv+0x293/0x850 fs/read_write.c:1019
       do_preadv fs/read_write.c:1133 [inline]
       __do_sys_preadv2 fs/read_write.c:1192 [inline]
       __se_sys_preadv2+0x17a/0x2a0 fs/read_write.c:1183
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (mapping.invalidate_lock#4){.+.+}-{4:4}:
       down_read+0x97/0x200 kernel/locking/rwsem.c:1574
       filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
       filemap_fault+0x6e0/0x13c0 mm/filemap.c:3570
       __do_fault+0x138/0x2a0 mm/memory.c:5425
       do_read_fault mm/memory.c:5860 [inline]
       do_fault mm/memory.c:5994 [inline]
       do_pte_missing+0x1828/0x28f0 mm/memory.c:4566
       handle_pte_fault mm/memory.c:6379 [inline]
       __handle_mm_fault mm/memory.c:6517 [inline]
       handle_mm_fault+0xd28/0x13f0 mm/memory.c:6686
       faultin_page mm/gup.c:1126 [inline]
       __get_user_pages+0x166b/0x2590 mm/gup.c:1428
       populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
       __mm_populate+0x25f/0x390 mm/gup.c:1963
       mm_populate include/linux/mm.h:4171 [inline]
       vm_mmap_pgoff+0x356/0x4e0 mm/util.c:586
       ksys_mmap_pgoff+0x4a6/0x720 mm/mmap.c:606
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       down_read_killable+0xa4/0x220 kernel/locking/rwsem.c:1599
       mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:601
       get_mmap_lock_carefully mm/mmap_lock.c:450 [inline]
       lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501
       do_user_addr_fault+0x341/0x1340 arch/x86/mm/fault.c:1366
       handle_page_fault arch/x86/mm/fault.c:1483 [inline]
       exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
       filldir64+0x2bc/0x620 fs/readdir.c:-1
       dir_emit include/linux/fs.h:3587 [inline]
       ntfs_dir_emit fs/ntfs3/dir.c:346 [inline]
       ntfs_read_hdr+0x8a4/0xc10 fs/ntfs3/dir.c:387
       ntfs_readdir+0x9ea/0xec0 fs/ntfs3/dir.c:547
       iterate_dir+0x2f1/0x4e0 fs/readdir.c:110
       __do_sys_getdents64 fs/readdir.c:399 [inline]
       __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> mapping.invalidate_lock#4 --> &ni->ni_lock/5

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->ni_lock/5);
                               lock(mapping.invalidate_lock#4);
                               lock(&ni->ni_lock/5);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz.1.865/13876:
 #0: ffff88803a096328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
 #1: ffff88803fb0dec8 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: iterate_dir+0x215/0x4e0 fs/readdir.c:103
 #2: ffff88803fb0dc10 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1222 [inline]
 #2: ffff88803fb0dc10 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_readdir+0x752/0xec0 fs/ntfs3/dir.c:499

stack backtrace:
CPU: 0 UID: 0 PID: 13876 Comm: syz.1.865 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 down_read_killable+0xa4/0x220 kernel/locking/rwsem.c:1599
 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:601
 get_mmap_lock_carefully mm/mmap_lock.c:450 [inline]
 lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501
 do_user_addr_fault+0x341/0x1340 arch/x86/mm/fault.c:1366
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0010:filldir64+0x2bc/0x620 fs/readdir.c:369
Code: fa 96 82 ff 0f 01 cb 48 8b 44 24 28 49 89 47 08 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 58 48 89 03 8b 4c 24 04 48 8d 43 10 <66> 89 08 8b 4c 24 14 80 e1 0f 48 8d 43 12 88 08 4a 8d 04 2b 48 83
RSP: 0018:ffffc90006297ab0 EFLAGS: 00050297
RAX: 0000200000001000 RBX: 0000200000000ff0 RCX: 0000000000000018
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000007
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10062dc001 R12: ffff88804401a000
R13: 0000000000000003 R14: 0000000000000003 R15: 0000200000000fd8
 dir_emit include/linux/fs.h:3587 [inline]
 ntfs_dir_emit fs/ntfs3/dir.c:346 [inline]
 ntfs_read_hdr+0x8a4/0xc10 fs/ntfs3/dir.c:387
 ntfs_readdir+0x9ea/0xec0 fs/ntfs3/dir.c:547
 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:399 [inline]
 __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcffbdcde99
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:00007fcffa005028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fcffc056090 RCX: 00007fcffbdcde99
RDX: 00000000000000e0 RSI: 0000200000000fc0 RDI: 0000000000000004
RBP: 00007fcffbe63eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcffc056128 R14: 00007fcffc056090 R15: 00007fffb5ebca68
 </TASK>
----------------
Code disassembly (best guess), 3 bytes skipped:
   0:	ff 0f                	decl   (%rdi)
   2:	01 cb                	add    %ecx,%ebx
   4:	48 8b 44 24 28       	mov    0x28(%rsp),%rax
   9:	49 89 47 08          	mov    %rax,0x8(%r15)
   d:	48 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbp
  14:	fc ff df
  17:	48 8b 44 24 58       	mov    0x58(%rsp),%rax
  1c:	48 89 03             	mov    %rax,(%rbx)
  1f:	8b 4c 24 04          	mov    0x4(%rsp),%ecx
  23:	48 8d 43 10          	lea    0x10(%rbx),%rax
* 27:	66 89 08             	mov    %cx,(%rax) <-- trapping instruction
  2a:	8b 4c 24 14          	mov    0x14(%rsp),%ecx
  2e:	80 e1 0f             	and    $0xf,%cl
  31:	48 8d 43 12          	lea    0x12(%rbx),%rax
  35:	88 08                	mov    %cl,(%rax)
  37:	4a 8d 04 2b          	lea    (%rbx,%r13,1),%rax
  3b:	48                   	rex.W
  3c:	83                   	.byte 0x83