Created attachment 283179 [details]
Corrupted f2fs image (compressed)

[Overview]
fsck.f2fs of f2fs-tools (master at commit 54244dcafd) triggers a division by zero error while fixing a corrupted image, in which segs->secs_per_zone is set to 0.

[Reproduction]
Download and uncompress the attached image.
Run fsck.f2fs against the downloaded image:
$ cd path/to/f2fs-tools/
$ ./fsck/fsck.f2fs -d 0 -f /tmp/f2fs.img
Info: Force to fix corruption
Info: Segments per section = 1
Info: Sections per zone = 1
Info: sector size = 512
Info: total sectors = 131072 (64 MB)
Info: MKFS version
  "Linux version 4.13.0-45-generic (buildd@lgw01-amd64-011) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.9)) #50~16.04.1-Ubuntu SMP Wed May 30 11:18:27 UTC 2018"
Info: FSCK version
  from "Linux version 4.13.0-45-generic (buildd@lgw01-amd64-011) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.9)) #50~16.04.1-Ubuntu SMP Wed May 30 11:18:27 UTC 2018"
    to "Linux version 4.18.0-21-generic (buildd@lcy01-amd64-006) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) #22~18.04.1-Ubuntu SMP Thu May 16 15:07:19 UTC 2019"
[update_superblock: 503] Info: Done to update superblock
Info: superblock features = 0 : 
Info: superblock encrypt level = 0, salt = 00000000000000000000000000000000
Info: total FS sectors = 131072 (64 MB)
Info: CKPT version = 3
[1]    13488 floating point exception (core dumped)  ./fsck/fsck.f2fs -f /tmp/f2fs.img

[Location]
- build_curseg at fsck/mount.c:1589
  1589  array[i].zone = GET_ZONENO_FROM_SEGNO(sbi, segno);
- GET_ZONENO_FROM_SEGNO(sbi, segno) at fsck/f2fs.h:317
  318 ((segno / sbi->segs_per_sec) / sbi->secs_per_zone)
Causes division by zero error when sbi->secs_per_zone is corrupted to be 0.