Re: [PATCH 1/3] libparted: fix a bug in the hfs probe functions (#714758)

[Jim Meyering]

Brian C. Lane wrote:
> From: "Brian C. Lane" <address@hidden>
>
> * libparted/fs/hfs/probe.c (hfsplus_probe): Add a check on the
>   search value and reject it if it is negative.
>   (hfsx_probe): Same
>   (hfs_and_wrapper_probe): Same

Thanks again.
I've adjusted your log and pushed that patch,
along with a test and a NEWS update:

>From 6bc7e1965078579e9855f851254d67b3d8165784 Mon Sep 17 00:00:00 2001
From: "Brian C. Lane" <address@hidden>
Date: Fri, 7 Oct 2011 16:53:48 -0700
Subject: [PATCH 1/2] libparted: HFS/HFS+ probe: don't let a corrupt FS evoke
 failed assertion

* libparted/fs/hfs/probe.c (hfsplus_probe): Add a check on the
search value and reject it if it is negative.
(hfsx_probe): Likewise.
(hfs_and_wrapper_probe): Likewise.
Reported by Flos Lonicerae in http://bugzilla.redhat.com/714758
---
 libparted/fs/hfs/probe.c |   18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/libparted/fs/hfs/probe.c b/libparted/fs/hfs/probe.c
index 8c656cf..bf4d70b 100644
--- a/libparted/fs/hfs/probe.c
+++ b/libparted/fs/hfs/probe.c
@@ -82,7 +82,8 @@ hfs_and_wrapper_probe (PedGeometry* geom)
                  + ((PedSector) PED_BE16_TO_CPU (mdb->total_blocks)
                     * (PED_BE32_TO_CPU (mdb->block_size) / 
PED_SECTOR_SIZE_DEFAULT )));
        max = search + (PED_BE32_TO_CPU (mdb->block_size) / 
PED_SECTOR_SIZE_DEFAULT);
-       if (!(geom_ret = ped_geometry_new (geom->dev, geom->start, search + 2)))
+       if ((search < 0)
+           || !(geom_ret = ped_geometry_new (geom->dev, geom->start, search + 
2)))
                return NULL;

        for (; search < max; search++) {
@@ -141,8 +142,9 @@ hfsplus_probe (PedGeometry* geom)
                      - 2;
                search = max - 2 * ( PED_BE32_TO_CPU (vh->block_size)
                                     / PED_SECTOR_SIZE_DEFAULT ) + 2;
-               if (!(geom_ret = ped_geometry_new (geom->dev, geom->start,
-                                                  search + 2)))
+               if ((search < 0)
+                   || !(geom_ret = ped_geometry_new (geom->dev, geom->start,
+                                                     search + 2)))
                        return NULL;

                for (; search < max; search++) {
@@ -156,8 +158,9 @@ hfsplus_probe (PedGeometry* geom)
                search = ((PedSector) PED_BE32_TO_CPU (vh->total_blocks) - 1)
                      * ( PED_BE32_TO_CPU (vh->block_size) / 
PED_SECTOR_SIZE_DEFAULT )
                      - 1;
-               if (!ped_geometry_set (geom_ret, geom_ret->start,
-                                              search + 2)
+               if ((search < 0)
+                   || !ped_geometry_set (geom_ret, geom_ret->start,
+                                         search + 2)
                    || !ped_geometry_read (geom_ret, buf, search, 1)
                    || vh->signature != PED_CPU_TO_BE16 (HFSP_SIGNATURE)) {
                        ped_geometry_destroy (geom_ret);
@@ -213,8 +216,9 @@ hfsx_probe (PedGeometry* geom)
                      * ( PED_BE32_TO_CPU (vh->block_size) / 
PED_SECTOR_SIZE_DEFAULT )
                      - 2;
        search = max - ( PED_BE32_TO_CPU (vh->block_size) / 
PED_SECTOR_SIZE_DEFAULT );
-       if (!(geom_ret = ped_geometry_new (geom->dev, geom->start,
-                                          search + 2)))
+       if ((search < 0)
+           || !(geom_ret = ped_geometry_new (geom->dev, geom->start,
+                                             search + 2)))
                return NULL;
        for (; search < max; search++) {
                if (!ped_geometry_set (geom_ret, geom_ret->start,
--
1.7.8.rc0.35.gee6df


>From 723ca1f12f13ae108eba611d72de26591e1214ba Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sat, 5 Nov 2011 20:49:18 +0100
Subject: [PATCH 2/2] tests: exercise and document the HFS-probe bug fix

Simply zeroing out the total_blocks and block_size members of the
on-disk _HfsMasterDirectoryBlock would provoke a failed assertion
any time parted tried to probe that partition.
* tests/t2500-probe-corrupt-hfs.sh: New script.
* tests/Makefile.am (TESTS): Add it.
* NEWS (Bug fixes): Mention this.
---
 .gitignore                       |    2 +-
 NEWS                             |    4 +++
 tests/Makefile.am                |    1 +
 tests/t2500-probe-corrupt-hfs.sh |   41 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 47 insertions(+), 1 deletions(-)
 create mode 100755 tests/t2500-probe-corrupt-hfs.sh

diff --git a/.gitignore b/.gitignore
index 5937e5b..98005db 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,9 +36,9 @@ libparted.pc
 libparted/tests/disk
 libparted/tests/init.sh
 libparted/tests/label
+libparted/tests/symlink
 libparted/tests/t*.sh.log
 libparted/tests/test-suite.log
-libparted/tests/symlink
 libparted/tests/zerolen
 libtool
 m4
diff --git a/NEWS b/NEWS
index c6e22f0..43b73f1 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,10 @@ GNU parted NEWS                                    -*- 
outline -*-
   cause an MSDOS partition table to be mistakenly identified as pc98.
   [bug present since the beginning]

+  libparted no longer gets a failed assertion when probing a partition
+  with an HFS or HFS+ signature, but with invalid ->total_blocks and/or
+  ->block_size values.
+
 ** Changes in behavior

   parted: mkpart command has changed semantics with regard to specifying end
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 71787e5..5bc513d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -35,6 +35,7 @@ TESTS = \
   t2300-dos-label-extended-bootcode.sh \
   t2310-dos-extended-2-sector-min-offset.sh \
   t2400-dos-hfs-partition-type.sh \
+  t2500-probe-corrupt-hfs.sh \
   t3200-type-change.sh \
   t3300-palo-prep.sh \
   t3310-flags.sh \
diff --git a/tests/t2500-probe-corrupt-hfs.sh b/tests/t2500-probe-corrupt-hfs.sh
new file mode 100755
index 0000000..435af9f
--- /dev/null
+++ b/tests/t2500-probe-corrupt-hfs.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+# Do not misbehave when probing a corrupt HFS partition.
+
+# Copyright (C) 2011 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/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../parted
+ss=$sector_size_
+
+N=3M
+dev=loop-file
+# create a file large enough to hold a GPT partition table
+dd if=/dev/null of=$dev bs=1 seek=$N || framework_failure
+
+parted -s "$dev" mklabel gpt mkpart p1 1MiB 2MiB > out 2>&1 || fail=1
+compare out /dev/null || fail=1
+
+parted -s "$dev" u s p || fail=1
+
+# Poke an HFS+ signature into place
+printf '\x48\x2b' | dd of=$dev seek=$((2048+2)) conv=notrunc || fail=1
+
+# Or, if starting from a valid HFS/HFS+ file system, poke these:
+# offset 18 total_blocks=0(16b)
+# offset 20 vh->block_size=0(32b)
+
+parted -s "$dev" u s p || fail=1
+
+Exit $fail
--
1.7.8.rc0.35.gee6df