Bug#613409: grub-pc: overwrites first sector of first partition

[Piotr Kaczuba]

Package: grub-pc
Version: 1.99~rc1-2
Severity: critical
Tags: upstream
Justification: causes serious data loss

Running grub-install during upgrade to 1.99~rc1-2, the following
message is shown:

/usr/sbin/grub-setup: warn: Sector 60 is already in use by FlexNet;
avoiding it.  This software may cause boot or other problems in future.
Please ask its authors not to store data in the boot track.
Installation finished. No error reported.


After that and a reboot, the first patition (FAT32) on the disk where
the MBR was installed is unusable. Neither GRUB nor the linux kernel
recognize it anymore:

[ 7209.380621] FAT: utf8 is not a recommended IO charset for FAT
filesystems, filesystem will be case sensitive!
[ 7209.396133] FAT: invalid media value (0xb3)
[ 7209.396140] VFS: Can't find a valid FAT filesystem on dev sdc1.


Looking in an hex editor at an image of it, it turns out that Grub
has overwritten the first sector of the partition. (Maybe because of the
unusable sector 60?)


-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (x86_64)

Kernel: Linux 2.6.37-orbiter.x86-64.1 (PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash