[Parted-commits] GNU Parted Official Repository: Changes to 'master'

Jim Meyering meyering at alioth.debian.org
Wed Feb 10 17:36:14 UTC 2010


 NEWS                                                        |    5 +
 libparted/labels/gpt.c                                      |    2 
 tests/Makefile.am                                           |    1 
 tests/t-local.sh                                            |   57 ++++++++++++
 tests/t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh |   56 +++++++++++
 tests/t0280-gpt-corrupt.sh                                  |   35 -------
 6 files changed, 125 insertions(+), 31 deletions(-)

New commits:
commit 432a33115c50005bbe96a09d55edc7d034715ec8
Author: Jim Meyering <meyering at redhat.com>
Date:   Wed Feb 10 17:11:25 2010 +0100

    gpt: "read-only" operation could clobber the pMBR in another way
    
    A read-only operation like "parted $dev print" would overwrite $dev's
    pMBR when exactly one of the primary and backup tables was corrupt.
    * libparted/labels/gpt.c (gpt_read): Clear "write_back" in those
    two cases.  Hans De Goede spotted this bug by inspection.
    * NEWS (Bug fixes): Mention it.
    * tests/t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh: New test.
    * tests/Makefile.am (TESTS): Add
    t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh.

diff --git a/NEWS b/NEWS
index 96ea96c..28f87de 100644
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,11 @@ GNU parted NEWS                                    -*- outline -*-
   gpt: read-only operation could clobber MBR part of hybrid GPT+MBR table
   [bug introduced in parted-2.1]
 
+  gpt: a read-only operation like "parted $dev print" would overwrite $dev's
+  protective MBR when exactly one of the primary and backup GPT tables was
+  found to be corrupt.
+  [bug introduced prior to parted-1.8.0]
+
   "make install" no longer installs tests programs named disk and label
 
 
diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c
index ea96a3b..48d580e 100644
--- a/libparted/labels/gpt.c
+++ b/libparted/labels/gpt.c
@@ -984,6 +984,7 @@ gpt_read (PedDisk *disk)
         goto error_free_gpt;
 
       gpt = primary_gpt;
+      write_back = 0;
     }
   else /* !primary_gpt && backup_gpt */
     {
@@ -996,6 +997,7 @@ gpt_read (PedDisk *disk)
         goto error_free_gpt;
 
       gpt = backup_gpt;
+      write_back = 0;
     }
   backup_gpt = NULL;
   primary_gpt = NULL;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 38922f6..8008400 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -10,6 +10,7 @@ TESTS = \
   t0201-gpt.sh \
   t0202-gpt-pmbr.sh \
   t0205-gpt-list-clobbers-pmbr.sh \
+  t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh \
   t0220-gpt-msftres.sh \
   t0250-gpt.sh \
   t0280-gpt-corrupt.sh \
diff --git a/tests/t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh b/tests/t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh
new file mode 100755
index 0000000..f47549e
--- /dev/null
+++ b/tests/t0206-gpt-print-with-corrupt-primary-clobbers-pmbr.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+# Ensure that printing a GPT partition table does not modify the pMBR.
+# Much like t0205, but with the addition of a corrupt PTE in primary table,
+# "parted $device print" would modify $device.
+
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  parted --version
+fi
+
+: ${srcdir=.}
+. $srcdir/t-lib.sh
+
+fail=0
+
+ss=$sector_size_
+n_sectors=400
+dev=dev-file
+
+dd if=/dev/null of=$dev bs=$ss seek=$n_sectors || fail=1
+parted -s $dev mklabel gpt                     || fail=1
+parted -s $dev mkpart p1 128s 255s             || fail=1
+
+parted -m -s $dev u s p                        || fail=1
+
+# Write non-NUL bytes all over the MBR, so we're likely to see any change.
+# However, be careful to leave the type of the first partition, 0xEE,
+# as well as the final two magic bytes.
+printf '%0450d\xee%059d\x55\xaa' 0 0 | dd of=$dev count=1 conv=notrunc || fail=1
+
+dd if=$dev of=before count=1 || fail=1
+
+orig_byte=$(gpt_corrupt_primary_table_ $dev $ss) || fail=1
+
+parted -m -s $dev u s p || fail=1
+
+dd if=$dev of=after count=1 || fail=1
+
+cmp before after || fail=1
+
+Exit $fail

commit 7a06dae72e336b16e6a412ddebe72fe03be2a3a9
Author: Jim Meyering <meyering at redhat.com>
Date:   Wed Feb 10 17:09:49 2010 +0100

    tests: factor utility functions into "library"
    
    ...since we're about to use them from a second test.
    * tests/t-local.sh (peek_, poke_, gpt1_pte_name_offset_): New functions.
    (gpt_corrupt_primary_table_, gpt_restore_primary_table_): New functions.
    * tests/t0280-gpt-corrupt.sh: Remove local copies of those functions.
    Use the new ones.

diff --git a/tests/t-local.sh b/tests/t-local.sh
index 096e67c..2e4ca4b 100644
--- a/tests/t-local.sh
+++ b/tests/t-local.sh
@@ -97,4 +97,61 @@ require_512_byte_sector_size_()
       || skip_test_ FS test with sector size != 512
 }
 
+peek_()
+{
+  case $# in 2) ;; *) echo "usage: peek_ FILE 0_BASED_OFFSET" >&2; exit 1;; esac
+  case $2 in *[^0-9]*) echo "peek_: invalid offset: $2" >&2; exit 1 ;; esac
+  dd if="$1" bs=1 skip="$2" count=1
+}
+
+poke_()
+{
+  case $# in 3) ;; *) echo "usage: poke_ FILE 0_BASED_OFFSET BYTE" >&2; exit 1;;
+    esac
+  case $2 in *[^0-9]*) echo "poke_: invalid offset: $2" >&2; exit 1 ;; esac
+  case $3 in ?) ;; *) echo "poke_: invalid byte: '$3'" >&2; exit 1 ;; esac
+  printf %s "$3" | dd of="$1" bs=1 seek="$2" count=1 conv=notrunc
+}
+
+# byte 56 of the partition entry is the first byte of its 72-byte name field
+gpt1_pte_name_offset_()
+{
+  local ss=$1
+  case $ss in *[^0-9]*) echo "$0: invalid sector size: $ss">&2; return 1;; esac
+  expr $ss \* 2 + 56
+  return 0
+}
+
+# Change the name of the first partition in the primary GPT table,
+# thus invalidating the PartitionEntryArrayCRC32 checksum.
+gpt_corrupt_primary_table_()
+{
+  case $# in 2) ;; *) echo "$0: expected 2 args, got $#" >&2; return 1;; esac
+  local dev=$1
+  local ss=$2
+  case $ss in *[^0-9]*) echo "$0: invalid sector size: $ss">&2; return 1;; esac
+
+  # get the first byte of the name
+  local orig_pte_name_byte=$(peek_ $dev $(gpt1_pte_name_offset_ $ss)) || return 1
+
+  local new_byte
+  test x"$orig_pte_name_byte" = xA && new_byte=B || new_byte=A
+
+  # Replace with a different byte
+  poke_ $dev $(gpt1_pte_name_offset_ $ss) "$new_byte" || return 1
+
+  printf %s "$orig_pte_name_byte"
+  return 0
+}
+
+gpt_restore_primary_table_()
+{
+  case $# in 3) ;; *) echo "$0: expected 2 args, got $#" >&2; return 1;; esac
+  local dev=$1
+  local ss=$2
+  case $ss in *[^0-9]*) echo "$0: invalid sector size: $ss">&2; return 1;; esac
+  local orig_byte=$3
+  poke_ $dev $(gpt1_pte_name_offset_ $ss) "$orig_byte" || return 1
+}
+
 . $srcdir/t-lvm.sh
diff --git a/tests/t0280-gpt-corrupt.sh b/tests/t0280-gpt-corrupt.sh
index 5c48116..5bf38f4 100755
--- a/tests/t0280-gpt-corrupt.sh
+++ b/tests/t0280-gpt-corrupt.sh
@@ -24,22 +24,6 @@ fi
 : ${srcdir=.}
 . $srcdir/t-lib.sh
 
-peek()
-{
-  case $# in 2) ;; *) echo "usage: peek FILE 0_BASED_OFFSET" >&2; exit 1;; esac
-  case $2 in *[^0-9]*) echo "peek: invalid offset: $2"; exit 1 ;; esac
-  dd if="$1" bs=1 skip="$2" count=1
-}
-
-poke()
-{
-  case $# in 3) ;; *) echo "usage: poke FILE 0_BASED_OFFSET BYTE" >&2; exit 1;;
-    esac
-  case $2 in *[^0-9]*) echo "poke: invalid offset: $2"; exit 1 ;; esac
-  case $3 in ?) ;; *) echo "poke: invalid byte: '$3'"; exit 1 ;; esac
-  printf %s "$3" | dd of="$1" bs=1 seek="$2" count=1 conv=notrunc
-}
-
 dev=loop-file
 
 ss=$sector_size_
@@ -67,17 +51,7 @@ compare /dev/null empty || fail=1
 
 # We're going to change the name of the first partition,
 # thus invalidating the PartitionEntryArrayCRC32 checksum.
-
-# byte 56 of the partition entry is the first byte of its 72-byte name field
-pte_offset=$(expr $ss \* 2 + 56)
-
-# get the first byte of the name
-pte_byte=$(peek $dev $pte_offset) || fail=1
-
-test x"$pte_byte" = xA && new_byte=B || new_byte=A
-
-# Replace with a different byte
-poke $dev $pte_offset "$new_byte" || fail=1
+orig_byte=$(gpt_corrupt_primary_table_ $dev $ss) || fail=1
 
 # printing the table must succeed, but with a scary diagnostic.
 parted -s $dev print > err 2>&1 || fail=1
@@ -91,9 +65,8 @@ compare exp err || fail=1
 # ----------------------------------------------------------
 # Now, restore things, and corrupt the MyLBA in the alternate GUID table.
 
-orig_byte=s
 # Restore original byte
-poke $dev $pte_offset "$orig_byte" || fail=1
+gpt_restore_primary_table_ $dev $ss "$orig_byte" || fail=1
 
 # print the table
 parted -s $dev print > out 2> err || fail=1
@@ -103,13 +76,13 @@ compare /dev/null err || fail=1
 # $n_sectors, 8-byte field starting at offset 24.
 alt_my_lba_offset=$(expr $n_sectors \* $ss - $ss + 24)
 # get the first byte of MyLBA
-byte=$(peek $dev $alt_my_lba_offset) || fail=1
+byte=$(peek_ $dev $alt_my_lba_offset) || fail=1
 
 # Perturb it.
 test x"$byte" = xA && new_byte=B || new_byte=A
 
 # Replace good byte with the bad one.
-poke $dev $alt_my_lba_offset "$new_byte" || fail=1
+poke_ $dev $alt_my_lba_offset "$new_byte" || fail=1
 
 # attempting to set partition name must print a diagnostic
 parted -m -s $dev name 1 foo > err 2>&1 || fail=1



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