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Daniel Axtens 2ca0e5dbcd fs/hfsplus: Don't use uninitialized data on corrupt filesystems
Valgrind identified the following use of uninitialized data:

  ==2782220== Conditional jump or move depends on uninitialised value(s)
  ==2782220==    at 0x42B364: grub_hfsplus_btree_search (hfsplus.c:566)
  ==2782220==    by 0x42B21D: grub_hfsplus_read_block (hfsplus.c:185)
  ==2782220==    by 0x42A693: grub_fshelp_read_file (fshelp.c:386)
  ==2782220==    by 0x42C598: grub_hfsplus_read_file (hfsplus.c:219)
  ==2782220==    by 0x42C598: grub_hfsplus_mount (hfsplus.c:330)
  ==2782220==    by 0x42B8C5: grub_hfsplus_dir (hfsplus.c:958)
  ==2782220==    by 0x4C1AE6: grub_fs_probe (fs.c:73)
  ==2782220==    by 0x407C94: grub_ls_list_files (ls.c:186)
  ==2782220==    by 0x407C94: grub_cmd_ls (ls.c:284)
  ==2782220==    by 0x4D7130: grub_extcmd_dispatcher (extcmd.c:55)
  ==2782220==    by 0x4045A6: execute_command (grub-fstest.c:59)
  ==2782220==    by 0x4045A6: fstest (grub-fstest.c:433)
  ==2782220==    by 0x4045A6: main (grub-fstest.c:772)
  ==2782220==  Uninitialised value was created by a heap allocation
  ==2782220==    at 0x483C7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==2782220==    by 0x4C0305: grub_malloc (mm.c:42)
  ==2782220==    by 0x42C21D: grub_hfsplus_mount (hfsplus.c:239)
  ==2782220==    by 0x42B8C5: grub_hfsplus_dir (hfsplus.c:958)
  ==2782220==    by 0x4C1AE6: grub_fs_probe (fs.c:73)
  ==2782220==    by 0x407C94: grub_ls_list_files (ls.c:186)
  ==2782220==    by 0x407C94: grub_cmd_ls (ls.c:284)
  ==2782220==    by 0x4D7130: grub_extcmd_dispatcher (extcmd.c:55)
  ==2782220==    by 0x4045A6: execute_command (grub-fstest.c:59)
  ==2782220==    by 0x4045A6: fstest (grub-fstest.c:433)
  ==2782220==    by 0x4045A6: main (grub-fstest.c:772)

This happens when the process of reading the catalog file goes sufficiently
wrong that there's an attempt to read the extent overflow file, which has
not yet been loaded. Keep track of when the extent overflow file is
fully loaded and refuse to use it before then.

The load valgrind doesn't like is btree->nodesize, and that's then used
to allocate a data structure. It looks like there are subsequently a lot
of reads based on that pointer so OOB reads are likely, and indeed crashes
(albeit difficult-to-replicate ones) have been observed in fuzzing.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
asm-tests asm-tests/i386-pc: Check that movl is 5 bytes. 2016-09-28 20:31:04 +03:00
conf gnulib/regcomp: Fix uninitialized re_token 2021-03-02 15:54:16 +01:00
docs docs: Document the cutmem command 2021-03-02 15:54:15 +01:00
grub-core fs/hfsplus: Don't use uninitialized data on corrupt filesystems 2021-03-02 15:54:18 +01:00
include fs/hfsplus: Don't use uninitialized data on corrupt filesystems 2021-03-02 15:54:18 +01:00
po po: Fix replacement of %m in sed programs 2020-03-10 21:32:09 +01:00
tests tests: F2FS test should use MOUNTDEVICE like other tests 2020-09-18 22:31:30 +02:00
themes/starfield Starfield theme. 2012-02-23 17:21:38 +01:00
unicode * unicode: Import Unicode 6.0 data. 2011-12-25 16:17:25 +01:00
util util/glue-efi: Fix incorrect use of a possibly negative value 2021-03-02 15:54:17 +01:00
.gitattributes gitattributes: Mark po/exclude.pot as binary so git won't try to diff nonprintables 2019-09-23 13:17:15 +02:00
.gitignore gitignore: Add a few forgotten file patterns 2020-05-15 15:06:21 +02:00
.travis.yml travis: Run bootstrap to fix build 2020-09-18 22:31:30 +02:00
acinclude.m4 Fix -nopie/-nopie check. 2017-01-30 19:38:55 +01:00
AUTHORS 2005-09-03 Yoshinori K. Okuji <okuji@enbug.org> 2005-09-03 16:54:27 +00:00
autogen.sh autogen: Replace -iname with -ipath in find command 2020-05-15 15:35:59 +02:00
bootstrap gnulib: Upgrade Gnulib and switch to bootstrap tool 2019-03-05 10:48:12 +01:00
bootstrap.conf gnulib/regcomp: Fix uninitialized re_token 2021-03-02 15:54:16 +01:00
BUGS * BUGS: New file. 2011-01-11 00:06:01 +01:00
ChangeLog-2015 Autogenerate ChangeLog from git changelog. 2015-01-24 17:29:50 +01:00
config.h.in Remove libgcc dependency. 2015-03-03 20:50:37 +01:00
configure.ac INSTALL/configure: Update install doc and configure comment 2020-05-25 14:49:53 +02:00
COPYING 2007-07-22 Yoshinori K. Okuji <okuji@enbug.org> 2007-07-21 23:32:33 +00:00
coreboot.cfg * coreboot.cfg: Add missing file. 2013-11-20 00:52:23 +01:00
geninit.sh automake commit without merge history 2010-05-06 11:34:04 +05:30
gentpl.py build: Fix GRUB i386-pc build with Ubuntu gcc 2020-03-31 12:17:02 +02:00
INSTALL safemath: Add some arithmetic primitives that check for overflow 2020-07-29 16:55:47 +02:00
linguas.sh linguas: Don't skip ko.po. 2017-02-04 00:06:57 +01:00
Makefile.am Makefile: Make libgrub.pp depend on config-util.h 2020-03-10 21:39:53 +01:00
Makefile.util.def Makefile: Remove unused GRUB_PKGLIBDIR definition 2020-10-30 21:53:00 +01:00
NEWS Release 2.04 2019-07-04 15:57:30 +02:00
README README: Remove dead link to the wiki 2015-11-06 04:31:23 +01:00
THANKS 2009-12-11 Robert Millan <rmh.grub@aybabtu.com> 2009-12-11 22:44:47 +00:00
TODO TODO: Remove obsolete link 2016-02-12 17:51:52 +01:00

This is GRUB 2, the second version of the GRand Unified Bootloader.
GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more
robust, more powerful, and more portable.

See the file NEWS for a description of recent changes to GRUB 2.

See the file INSTALL for instructions on how to build and install the
GRUB 2 data and program files.

Please visit the official web page of GRUB 2, for more information.
The URL is <http://www.gnu.org/software/grub/grub.html>.

More extensive documentation is available in the Info manual,
accessible using 'info grub' after building and installing GRUB 2.

There are a number of important user-visible differences from the
first version of GRUB, now known as GRUB Legacy. For a summary, please
see:

  info grub Introduction 'Changes from GRUB Legacy'