syzbot

loop2: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.528/10819 is trying to acquire lock:
ffff88804057dd30 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
ffff88804057dd30 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_fallocate+0x7f3/0x1140 fs/ntfs3/file.c:690

but task is already holding lock:
ffff88804057e1b8 (mapping.invalidate_lock#9){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1083 [inline]
ffff88804057e1b8 (mapping.invalidate_lock#9){++++}-{4:4}, at: ntfs_fallocate+0x3c3/0x1140 fs/ntfs3/file.c:620

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (mapping.invalidate_lock#9){++++}-{4:4}:
       down_read+0x97/0x200 kernel/locking/rwsem.c:1537
       filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
       filemap_fault+0x66f/0x12f0 mm/filemap.c:3537
       __do_fault+0x138/0x390 mm/memory.c:5323
       do_read_fault mm/memory.c:5758 [inline]
       do_fault mm/memory.c:5892 [inline]
       do_pte_missing+0x18d3/0x2e60 mm/memory.c:4404
       handle_pte_fault mm/memory.c:6276 [inline]
       __handle_mm_fault mm/memory.c:6414 [inline]
       handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6583
       do_user_addr_fault+0x75b/0x1360 arch/x86/mm/fault.c:1385
       handle_page_fault arch/x86/mm/fault.c:1474 [inline]
       exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
       fault_in_readable+0x8e/0x130 mm/gup.c:-1
       fault_in_iov_iter_readable+0x1b4/0x2f0 lib/iov_iter.c:106
       generic_perform_write+0x765/0x8b0 mm/filemap.c:4363
       ntfs_file_write_iter+0x74b/0x870 fs/ntfs3/file.c:1319
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x629/0xba0 fs/read_write.c:688
       ksys_pwrite64 fs/read_write.c:795 [inline]
       __do_sys_pwrite64 fs/read_write.c:803 [inline]
       __se_sys_pwrite64 fs/read_write.c:800 [inline]
       __x64_sys_pwrite64+0x19c/0x230 fs/read_write.c:800
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault+0xcb/0x130 mm/memory.c:7177
       _inline_copy_to_user include/linux/uaccess.h:201 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:236 [inline]
       fiemap_fill_next_extent+0x1dd/0x3c0 fs/ioctl.c:144
       ni_fiemap+0x9a5/0xca0 fs/ntfs3/frecord.c:2009
       ntfs_fiemap+0x11d/0x1a0 fs/ntfs3/file.c:1420
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x126f/0x1540 fs/ioctl.c:531
       __do_sys_ioctl fs/ioctl.c:595 [inline]
       __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ni->ni_lock#2/5){+.+.}-{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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
       ntfs_fallocate+0x7f3/0x1140 fs/ntfs3/file.c:690
       vfs_fallocate+0x672/0x7f0 fs/open.c:340
       ksys_fallocate fs/open.c:364 [inline]
       __do_sys_fallocate fs/open.c:369 [inline]
       __se_sys_fallocate fs/open.c:367 [inline]
       __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 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:
  &ni->ni_lock#2/5 --> &mm->mmap_lock --> mapping.invalidate_lock#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(mapping.invalidate_lock#9);
                               lock(&mm->mmap_lock);
                               lock(mapping.invalidate_lock#9);
  lock(&ni->ni_lock#2/5);

 *** DEADLOCK ***

3 locks held by syz.2.528/10819:
 #0: ffff888036ffe480 (sb_writers#27){++++}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
 #0: ffff888036ffe480 (sb_writers#27){++++}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:339
 #1: ffff88804057dfe8 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #1: ffff88804057dfe8 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: ntfs_fallocate+0x2f1/0x1140 fs/ntfs3/file.c:606
 #2: ffff88804057e1b8 (mapping.invalidate_lock#9){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1083 [inline]
 #2: ffff88804057e1b8 (mapping.invalidate_lock#9){++++}-{4:4}, at: ntfs_fallocate+0x3c3/0x1140 fs/ntfs3/file.c:620

stack backtrace:
CPU: 0 UID: 0 PID: 10819 Comm: syz.2.528 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
 ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
 ntfs_fallocate+0x7f3/0x1140 fs/ntfs3/file.c:690
 vfs_fallocate+0x672/0x7f0 fs/open.c:340
 ksys_fallocate fs/open.c:364 [inline]
 __do_sys_fallocate fs/open.c:369 [inline]
 __se_sys_fallocate fs/open.c:367 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f767b6bbf79
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:00007f7679916028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f767b935fa0 RCX: 00007f767b6bbf79
RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000004
RBP: 00007f767b7527e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f767b936038 R14: 00007f767b935fa0 R15: 00007ffc8cd3aac8
 </TASK>