[Bug 898012] [NEW] cannot install grub to zeroed mbr

Brian Milliron b_milliron at hotmail.com
Wed Nov 30 05:22:19 UTC 2011 

Public bug reported:

Background: Looking at raw data for my MBR I saw grub had not
overwritten old data from previous installation that was wiped on
suspicion of rootkit infection.  I zeroed MBR manually and grub could
not install.  Restoring old MBR allows grub install to complete without
error.  However, since grub-install does not fully overwrite existing
data, a user who wants confidence the entire MBR is clean must zero it
out.  This behavior could make cleaning bootkits impossible.

Troubleshooting steps already taken:
sudo grub-mkdevicemap
sudo grub-mkconfig
sudo update-grub2
sudo grub-setup -r /dev/mapper/group0-root /dev/sda
switching (hd0) and (hd1) in device.map has no effect


Steps to reproduce:

Step 1 sudo dd if=/dev/zero of=/dev/sda bs=512 count=63
Step 2 sudo grub-install /dev/sda (error below)
Step 3 sudo dd if=~/backup.mbr of=/dev/sda bs=512 count=63 
Step 4 sudo grub-install /dev/sda (no error)

Error messages:
sudo grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: info: /dev/sda3 starts from 62926848.
grub-probe: info: opening the device hd0.
grub-probe: info: the size of hd0 is 117210240.
grub-probe: error: cannot find a GRUB drive for /dev/sda3.  Check your device.map.

device.map
(hd0)   /dev/disk/by-id/mmc-00000_XXXXXXXXXX
(hd1)   /dev/disk/by-id/ata-TOSHIBA_XXXXXXXXXXXX_XXXXXXXXXX


Fdisk output:
Disk /dev/sda: 60.0 GB, 60011642880 bytes
255 heads, 63 sectors/track, 7296 cylinders, total 117210240 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: XXXXXXXXXXXXX

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048    52434943    26216448   83  Linux
/dev/sda2        52434944    62926847     5245952   83  Linux
/dev/sda3   *    62926848    63318015      195584   83  Linux
/dev/sda4        63318016   117209087    26945536   83  Linux

Disk /dev/mapper/sda4_crypt: 27.6 GB, 27591176192 bytes
255 heads, 63 sectors/track, 3354 cylinders, total 53889016 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/sda4_crypt doesn't contain a valid partition table

Disk /dev/mapper/group0-root: 9588 MB, 9588178944 bytes
255 heads, 63 sectors/track, 1165 cylinders, total 18726912 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/group0-root doesn't contain a valid partition table

Disk /dev/mapper/group0-var: 9588 MB, 9588178944 bytes
255 heads, 63 sectors/track, 1165 cylinders, total 18726912 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/group0-var doesn't contain a valid partition table

Disk /dev/mapper/group0-home: 5398 MB, 5398069248 bytes
255 heads, 63 sectors/track, 656 cylinders, total 10543104 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/group0-home doesn't contain a valid partition table

Disk /dev/mapper/group0-tmp: 645 MB, 645922816 bytes
255 heads, 63 sectors/track, 78 cylinders, total 1261568 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/group0-tmp doesn't contain a valid partition table

Disk /dev/mapper/group0-swap: 956 MB, 956301312 bytes
255 heads, 63 sectors/track, 116 cylinders, total 1867776 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/group0-swap doesn't contain a valid partition table

Disk /dev/mmcblk0: 32.3 GB, 32295092224 bytes
64 heads, 32 sectors/track, 30799 cylinders, total 63076352 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: XXXXXXXXXXXX

        Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1   *          32      411647      205808   83  Linux
/dev/mmcblk0p2          411678    63076351    31332337    5  Extended
/dev/mmcblk0p5          411680    63076351    31332336   83  Linux

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: grub-common 1.99-12ubuntu5
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
Uname: Linux 3.0.0-13-generic i686
ApportVersion: 1.23-0ubuntu4
Architecture: i386
Date: Tue Nov 29 22:31:25 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111011)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub2
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: grub2 (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: apport-bug i386 oneiric running-unity

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https://bugs.launchpad.net/bugs/898012

Title:
  cannot install grub to zeroed mbr

Status in “grub2” package in Ubuntu:
  New

Bug description:
  Background: Looking at raw data for my MBR I saw grub had not
  overwritten old data from previous installation that was wiped on
  suspicion of rootkit infection.  I zeroed MBR manually and grub could
  not install.  Restoring old MBR allows grub install to complete
  without error.  However, since grub-install does not fully overwrite
  existing data, a user who wants confidence the entire MBR is clean
  must zero it out.  This behavior could make cleaning bootkits
  impossible.

  Troubleshooting steps already taken:
  sudo grub-mkdevicemap
  sudo grub-mkconfig
  sudo update-grub2
  sudo grub-setup -r /dev/mapper/group0-root /dev/sda
  switching (hd0) and (hd1) in device.map has no effect

  
  Steps to reproduce:

  Step 1 sudo dd if=/dev/zero of=/dev/sda bs=512 count=63
  Step 2 sudo grub-install /dev/sda (error below)
  Step 3 sudo dd if=~/backup.mbr of=/dev/sda bs=512 count=63 
  Step 4 sudo grub-install /dev/sda (no error)

  Error messages:
  sudo grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub
  grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: scanning hd0 for LVM.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: no LVM signature found.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: scanning hd0 for LVM.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: no LVM signature found.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: info: /dev/sda3 starts from 62926848.
  grub-probe: info: opening the device hd0.
  grub-probe: info: the size of hd0 is 117210240.
  grub-probe: error: cannot find a GRUB drive for /dev/sda3.  Check your device.map.

  device.map
  (hd0)   /dev/disk/by-id/mmc-00000_XXXXXXXXXX
  (hd1)   /dev/disk/by-id/ata-TOSHIBA_XXXXXXXXXXXX_XXXXXXXXXX

  
  Fdisk output:
  Disk /dev/sda: 60.0 GB, 60011642880 bytes
  255 heads, 63 sectors/track, 7296 cylinders, total 117210240 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: XXXXXXXXXXXXX

     Device Boot      Start         End      Blocks   Id  System
  /dev/sda1            2048    52434943    26216448   83  Linux
  /dev/sda2        52434944    62926847     5245952   83  Linux
  /dev/sda3   *    62926848    63318015      195584   83  Linux
  /dev/sda4        63318016   117209087    26945536   83  Linux

  Disk /dev/mapper/sda4_crypt: 27.6 GB, 27591176192 bytes
  255 heads, 63 sectors/track, 3354 cylinders, total 53889016 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/sda4_crypt doesn't contain a valid partition table

  Disk /dev/mapper/group0-root: 9588 MB, 9588178944 bytes
  255 heads, 63 sectors/track, 1165 cylinders, total 18726912 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/group0-root doesn't contain a valid partition table

  Disk /dev/mapper/group0-var: 9588 MB, 9588178944 bytes
  255 heads, 63 sectors/track, 1165 cylinders, total 18726912 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/group0-var doesn't contain a valid partition table

  Disk /dev/mapper/group0-home: 5398 MB, 5398069248 bytes
  255 heads, 63 sectors/track, 656 cylinders, total 10543104 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/group0-home doesn't contain a valid partition table

  Disk /dev/mapper/group0-tmp: 645 MB, 645922816 bytes
  255 heads, 63 sectors/track, 78 cylinders, total 1261568 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/group0-tmp doesn't contain a valid partition table

  Disk /dev/mapper/group0-swap: 956 MB, 956301312 bytes
  255 heads, 63 sectors/track, 116 cylinders, total 1867776 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

  Disk /dev/mapper/group0-swap doesn't contain a valid partition table

  Disk /dev/mmcblk0: 32.3 GB, 32295092224 bytes
  64 heads, 32 sectors/track, 30799 cylinders, total 63076352 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: XXXXXXXXXXXX

          Device Boot      Start         End      Blocks   Id  System
  /dev/mmcblk0p1   *          32      411647      205808   83  Linux
  /dev/mmcblk0p2          411678    63076351    31332337    5  Extended
  /dev/mmcblk0p5          411680    63076351    31332336   83  Linux

  ProblemType: Bug
  DistroRelease: Ubuntu 11.10
  Package: grub-common 1.99-12ubuntu5
  ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
  Uname: Linux 3.0.0-13-generic i686
  ApportVersion: 1.23-0ubuntu4
  Architecture: i386
  Date: Tue Nov 29 22:31:25 2011
  InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111011)
  ProcEnviron:
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: grub2
  UpgradeStatus: No upgrade log present (probably fresh install)

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