fsck.msdos -n exited with status code 1
Warning: Filesystem is FAT32 according to fat_length and fat32_length fields,
  but has only 11 clusters, less than the required minimum of 65525.
  This may lead to problems on some systems.
fsck.fat 4.2 (2021-01-31)
There are differences between boot sector and its backup.
This is mostly harmless. Differences: (offset:original/backup)
  26:69/02, 44:06/02, 61:3d/00, 62:32/00, 94:7c/7f, 95:ac/00, 96:22/00
  , 97:c0/00, 98:74/00, 99:0b/00, 100:56/00, 101:b4/00, 103:07/bb, 129:74/ff
  , 130:20/01, 131:61/00, 132:20/00, 185:0a/03, 186:70/00, 196:02/6b
  , 197:00/65, 203:08/74, 204:00/72, 205:00/79, 206:00/20, 207:00/61
  , 208:00/67, 209:00/61, 210:00/69, 223:08/00, 460:06/00, 501:e1/00
  , 502:ff/00, 511:aa/40
  Not automatically fixing this.
FATs differ but appear to be intact.
  Using first FAT.
/.
  Bad short file name (.).
  Auto-renaming it.
  Renamed to FSCK0000.000
/.. 
  Bad short file name (.. ).
  Auto-renaming it.
  Renamed to FSCK0000.001
/FSCK0000.000
  Start cluster beyond limit (134217731 > 12). Truncating file.
/FSCK0000.001
  Directory has non-zero size. Fixing it.
/FSCK0000.001
 Start does point to root directory. Deleting dir. 
/SYZKALLE.R
  Start cluster beyond limit (65536 > 12). Truncating file.
/FILE0
  File size is 0 bytes, cluster chain length is > 0 bytes.
  Truncating file to 0 bytes.
/  and
/FILE2
  share clusters.
  Truncating second to 0 bytes because first is FAT32 root dir.
/FILE2
  File size is 9000 bytes, cluster chain length is 0 bytes.
  Truncating file to 0 bytes.
Label in boot sector is 'SYZKALLER', but there is no volume label in root directory.
  Auto-removing label from boot sector.
Reclaimed 2 unused clusters (8192 bytes).
Free cluster summary wrong (3 vs. really 5)
  Auto-correcting.

Leaving filesystem unchanged.
/tmp/245115686.img: 7 files, 6/11 clusters