Bug#403426: linux-image-2.6.18-3-ixp4xx: kernel corrupts LUKS partition header on arm NSLU2
Package: linux-image-2.6.18-3-ixp4xx
Version: 2.6.18-8
Severity: critical
Justification: causes serious data loss
This is on an NSLU2, I wanted to use it to access some disks that I
had used previously on another system that had encrypted partitons.
However, when I tried cryptsetup luksOpen, I got a automatic header
conversion from 0.99 to 0.991 triggered message, and then an infinite
loop. Trying the same partition on the other system, now I get the
same thing - its header is corrupted. Luckily, I'm paranoid and had a
backup of the LUKS header! If I didn't have this, the whole
partition's data would probably be lost.
Here's the result of some tests - and its stranger than you think...
Used cryptsetup luksFormat on another system to set up a partition..
LKG8A754B:~# uname -a
Linux LKG8A754B 2.6.18-3-ixp4xx #1 Mon Dec 11 17:20:00 UTC 2006 armv5tel GNU/Linux
!!! ... after some experiments corrupting it... now I restore it again
and decide to strace things... !!!
LKG8A754B:~# dd < sde4-luks-header-backup > /dev/sde4
150+0 records in
150+0 records out
76800 bytes (77 kB) copied, 0.0148216 seconds, 5.2 MB/s
LKG8A754B:~# strace 2>trace cryptsetup luksOpen /dev/sde4 sde4
Enter LUKS passphrase:
key slot 0 unlocked.
!!! Hey, that just worked !!!
LKG8A754B:~# ls -l /dev/mapper/sde4
brw-rw---- 1 root disk 254, 0 Dec 17 02:00 /dev/mapper/sde4
LKG8A754B:~# cmp -l /dev/sde4 sde4-luks-header-backup
cmp: EOF on sde4-luks-header-backup
!!! But: !!!
LKG8A754B:~# cryptsetup remove sde4
!!! no strace !!!
LKG8A754B:~# cryptsetup luksOpen /dev/sde4 sde4
Enter LUKS passphrase:
automatic header conversion from 0.99 to 0.991 triggered
<ctrl-c>
LKG8A754B:~# cmp -l /dev/sde4 sde4-luks-header-backup
168 0 12
513 114 0
514 125 0
515 113 0
516 123 0
517 272 0
518 276 0
520 1 0
521 141 0
522 145 0
523 163 0
539 0 3
540 0 10
543 0 17
544 0 240
553 143 0
554 142 0
555 143 0
556 55 0
557 145 0
558 163 0
559 163 0
560 151 0
561 166 0
562 72 0
563 163 0
564 150 0
565 141 0
566 62 0
567 65 0
568 66 0
585 163 0
586 150 0
587 141 3
588 61 210
591 0 17
592 0 240
cmp: EOF on sde4-luks-header-backup
LKG8A754B:~#
!!!
Its done something like overwrite the second sector of the header with
the first one. I had a look at the cryptsetup code, and the conversion
message is triggered by it finding the wrong state code for the
passphrase slot - so the data has been overwritten by the time its got
there.
This is reliable - it always seems to corrupt it without strace,
always works with!???
Err....
-- System Information:
Debian Release: 4.0
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing')
Architecture: arm (armv5tel)
Shell: /bin/sh linked to /bin/dash
Kernel: Linux 2.6.18-3-ixp4xx
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Versions of packages linux-image-2.6.18-3-ixp4xx depends on:
ii coreutils 5.97-5 The GNU core utilities
ii debconf [debconf-2.0] 1.5.8 Debian configuration management sy
ii initramfs-tools [linux-initra 0.85c tools for generating an initramfs
ii module-init-tools 3.3-pre3-1 tools for managing Linux kernel mo
linux-image-2.6.18-3-ixp4xx recommends no packages.
-- debconf information:
linux-image-2.6.18-3-ixp4xx/preinst/failed-to-move-modules-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/preinst/overwriting-modules-2.6.18-3-ixp4xx: true
shared/kernel-image/really-run-bootloader: true
linux-image-2.6.18-3-ixp4xx/postinst/kimage-is-a-directory:
linux-image-2.6.18-3-ixp4xx/preinst/lilo-has-ramdisk:
linux-image-2.6.18-3-ixp4xx/preinst/lilo-initrd-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/preinst/elilo-initrd-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/preinst/initrd-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/preinst/bootloader-initrd-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/postinst/old-initrd-link-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/preinst/abort-install-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/postinst/old-system-map-link-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/postinst/old-dir-initrd-link-2.6.18-3-ixp4xx: true
* linux-image-2.6.18-3-ixp4xx/preinst/already-running-this-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/postinst/bootloader-error-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/postinst/depmod-error-2.6.18-3-ixp4xx: false
linux-image-2.6.18-3-ixp4xx/prerm/would-invalidate-boot-loader-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/prerm/removing-running-kernel-2.6.18-3-ixp4xx: true
linux-image-2.6.18-3-ixp4xx/postinst/bootloader-test-error-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/preinst/abort-overwrite-2.6.18-3-ixp4xx:
linux-image-2.6.18-3-ixp4xx/postinst/depmod-error-initrd-2.6.18-3-ixp4xx: false
linux-image-2.6.18-3-ixp4xx/postinst/create-kimage-link-2.6.18-3-ixp4xx: true
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