[Pkg-zfsonlinux-devel] Bug#982277: zfs-dkms: ZFS is not validating checksums on file read.

[Stefan Arnold]

Package: zfs-dkms
Version: 0.8.6-1~bpo10+1
Severity: important
Tags: upstream

ZFS seems to not recognize data errors without doing a scrub.

Steps to reproduce:
- create a small partition (1GB)
- "zpool create -m /zfs zfspool /dev/..."
- create a 800MB testfile "dd if=/dev/zero of=/zfs/testfile bs=1M count=800"
- "shasum /zfs/testfile" -> checksum A
- change a byte somwhere in /dev/...
- empty caches "sync; echo 3 > /proc/sys/vm/drop_caches"
- "shasum /zfs/testfile" -> checksum B
- "zpool status" shows no errors
- checksums A and B differ, the file is corrupted without being noticed
- do "zpool scrub zfspool"
- "zpool status" shows the error

Version 2.0.2 has the same issue. According to another guy version 0.8.4 from
Ubuntu is not affected.



-- System Information:
Debian Release: 10.8
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.9.0-0.bpo.5-amd64 (SMP w/4 CPU cores)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8), LANGUAGE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages zfs-dkms depends on:
ii  debconf [debconf-2.0]  1.5.71
ii  dkms                   2.6.1-4
ii  file                   1:5.35-4+deb10u2
ii  libc6-dev [libc-dev]   2.28-10
ii  libpython3-stdlib      3.7.3-1
ii  lsb-release            10.2019051400
ii  perl                   5.28.1-6+deb10u1
ii  python3-distutils      3.7.3-1

Versions of packages zfs-dkms recommends:
ii  linux-libc-dev  4.19.171-2
pn  zfs-zed         <none>
pn  zfsutils-linux  <none>

Versions of packages zfs-dkms suggests:
ii  debhelper  12.1.1

-- debconf information excluded