This addresses a potential security vulnerability where an untrusted
filesystem can be corrupted in such a way that a program using
libext2fs will allocate a buffer which is far too small. This can
lead to either a crash or potentially a heap-based buffer overflow
crash. No known exploits exist, but main concern is where an
untrusted user who possesses privileged access in a guest Xen
environment could corrupt a filesystem which is then accessed by the
pygrub program, running as root in the dom0 host environment, thus
allowing the untrusted user to gain privileged access in the host OS.
Thanks to the McAfee AVERT Research group for reporting this issue.
Addresses CVE-2007-5497.
Signed-off-by: Rafal Wojtczuk <rafal_wojtczuk@mcafee.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
superblock. E2fsck will automatically save the journal information
in the superblock if it is not there already, and will use it if the
journal inode appears to be corrupted. ext2fs_add_journal_inode()
will also save the backup information, so that new filesystems
created by mke2fs and filesystems that have journals added via
tune2fs will also have journal location written to the superblock as
well. Debugfs's logdump command has been enhanced so that it can
use the journal information in the superblock.
The debugfs man page has been improved to more fully describe the
logdump command.
Added two new functions, ext2fs_file_open2() and
ext2fs_inode_io_intern2() which take a pointer to an inode structure;
this is needed so that e2fsck and debugfs can synthesize a
fake journal inode and use it to access the journal.
an I/O object.
Export ext2_file_flush as a public interface.
Also minor cleanups to tighten code in other I/O abstractions, and to
mark a void * pointer as const in the ext2_file_write interface.
fileio.c (ext2fs_file_read): Factored out common code and cleaned up
function. Fixed a bug where if there was an error reading from the
disk, the number of bytes read wasn't reliably set. (Fixes Debian bug
#79163)
(ext2fs_file_write): Factored out common code and made function more
efficient; if writing a full block, don't bother to do a
read-modify-write cycle.
alloc.c, bb_inode.c, bitmaps.c, bitops.h, block.c, bmap.c, bmove.c,
brel.h, cmp_bitmaps.c, dblist.c, dblist_dir.c, dir_iterate.c,
expanddir.c, ext2fs.h, ext2fsP.h, fileio.c, finddev.c, get_pathname.c,
icount.c, inode.c, irel.h, irel_ma.c, ismounted.c, link.c, lookup.c,
mkdir.c, mkjournal.c, namei.c, newdir.c, read_bb_file.c, test_io.c,
tst_iscan.c, unix_io.c, unlink.c: Change use of ino_t to ext2_ino_t,
to protect applications that attempt to compile
-D_FILE_OFFSET_BITS=64, since this inexplicably changes ino_t(!?). So
we use ext2_ino_t to avoid an unexpected ABI change.
fileio.c (ext2fs_file_open): Remove obsolete comment stating that we
don't handle writing yet (we do). Fixed bug where we weren't
allocating a big enough buffer for ext2_bmap.
ChangeLog, ext2fs.h:
ext2fs.h: Add feature definition for AFS IMAGIC inodes.
ChangeLog, MCONFIG.in, config.sub:
MCONFIG.in: Define man1dir, man3dir, and man8dir in terms of mandir.
config.sub: Update config.sub from autoconf 2.13 so that it will
recognize new machine types from the Alpha.
configure:
Update to match latest changes to configure.in
rw_bitmaps.c: Fixed signed/unsigned warnings.
fileio.c (ext2fs_file_set_size): Remove unneeded extern from the
function declaration.
dblist.c (make_dblist): Add safety check in case the dblist pointer
passed in is null (in which case, assign it to fs->dblist). Fixed
some signed/unsigned warnings.
bmap.c: Make addr_per_block be of type blk_t to avoid signed/unsigned
warnings.
namei.c (ext2fs_follow_link): Remove uneeded extern from the function
declaration.
get_pathname.c (get_pathname_proc): Use return value from
ext2fs_get_mem, instead of checking if &gp->name is NULL.
dir_iterate.c (ext2fs_process_dir_block):
dblist_dir.c (ext2fs_dblist_dir_iterate): Remove uneeded extern from
the function declaration.
block.c (ext2fs_block_iterate2): If the read_inode call fails, return
the error directly instead of jumping to the cleanup routine, since we
don't need to do any cleanup.
alloc_table.c (ext2fs_allocate_group_table): Make this function take a
dgrp_t for its group argument.
ext2fs.h: Make dgrp_t an __u32 type, and make fs->desc_group_count be
of type dgrp_t.
ext2fs.h: Add new superblock fields (s_algorithm_usage_bitmap,
s_prealloc_blocks, s_prealloc_dir_blocks). Added conditional defines
of new features COMPAT_DIR_PREALLOC, RO_COMPAT_LARGE_FILE
RO_COMPAT_BTREE_DIR, INCOMPAT_COMPRESSION, INCOMPAT_DIRNAME_SIZE.
Changed the library to declare that we support COMPAT_DIR_PREALLOC,
INCOMPAT_DIRNAME_SIZE, RO_COMPAT_LARGE_FILE.
fileio.c: Rename function ext2fs_file_llseek to be ext2fs_file_lseek,
which is more accurate.
block.c: Add new function ext2fs_block_iterate3 which calls the
iterator function with the blockcount argument of type blkcnt_t. This
version of the function is allowed to handle large files; the other
fucntions are not.
ext2fs.h: Add new type blkcnt_t
ext2_err.et.in: Add error code EXT2_ET_FILE_TOO_BIG
block.c (ext2fs_block_iterate2): Fix bug where the block count field
wasn't getting correctly incremented for sparse files when the
indirect or doubly-indirect block specified in the inode was zero.
unlink.c (unlink_proc):
lookup.c (lookup_proc):
link.c (link_proc):
get_pathname.c (get_pathname_proc):
dir_iterate.c (ext2fs_process_dir_block): Mask off high 8 bits from
dirent->name_len, so it can be used for other purposes.
ext2fs.h: Add definition of EXT2_FEATURE_INCOMPAT_DIRNAME_SIZE, and
indicate that we have support for this incompatible option.
inode.c (ext2fs_open_inode_scan): Initialize the group variables
so that we don't need to call get_next_blockgroup() the first
time around. Saves a bit of time, and prevents us from
needing to assign -1 to current_group (which is an unsigned
value).
icount.c (insert_icount_el): Cast the estimated number of inodes
from a float to an ino_t.
alloc.c, alloc_tables.c, badlbocks.c, bb_compat.c, bb_inode.c,
bitmaps.c, bitops.c, block.c, bmap.c, bmove.c, brel_ma.c,
check_desc.c, closefs.c, cmp_bitmaps.c, dblist.c,
dblist_dir.c, dir_iterate.c, dirblock.c, dupfs.c, expanddir.c,
ext2fs.h, fileio.c, freefs.c, get_pathname.c, getsize.c,
icount.c, initialize.c, inline.c, inode.c, irel_ma.c,
ismounted.c, link.c, lookup.c, mkdir.c, namei.c, native.c,
newdir.c, openfs.c, read_bb.c, read_bb_file.c, rs_bitmap.c,
rw_bitmaps.c, swapfs.c, test_io.c, tst_badblocks.c,
tst_getsize.c, tst_iscan.c, unix_io.c, unlink.c, valid_blk.c,
version.c: If EXT2_FLAT_INCLUDES is defined, then assume all
of the ext2-specific header files are in a flat directory.
block.c, bmove.c, dirblock.c, fileio.c: Explicitly cast
all assignments from void * to be compatible with C++.
closefs.c (ext2fs_flush): Add a call to io_channel_flush() to
make sure the contents of the disk are flushed to disk.
dblist.c (ext2fs_add_dir_block): Change new to be new_entry to
avoid C++ namespace clash.
bitmaps.c (ext2fs_copy_bitmap): Change new to be new_map to
avoid C++ namespace clash.
ext2fs.h, bb_inode.c, block.c, bmove.c, brel.h, brel_ma.c,
irel.h, irel_ma.c, dblist.c, dblist_dir.c, dir_iterate.c,
ext2fsP.h, expanddir.c, get_pathname.c, inode.c, link.c,
unlink.c: Change private to be priv_data (to avoid C++
namespace clash)
dblist.c (ext2fs_get_num_dirs): Make ext2fs_get_num_dirs more paranoid
about validating the directory counts from the block group
information.
all files: Don't include stdlib.h anymore; include it in ext2_fs.h,
since that file requires stdlib.h
ChangeLog, Makefile.in, dirinfo.c:
dirinfo.c (e2fsck_add_dir_info): Use ext2fs_get_num_dirs instead of
e2fsck_get_num_dirs, which has been removed.
Makefile.in (PROGS): Remove @EXTRA_PROGS@, since we don't want to
compile and install flushb.
ChangeLog, configure.in:
Remove @EXTRA_PROGS@, since we aren't using it in 2fsck/Makefile.in anymore
ChangeLog, Makefile.in:
Install debugfs in /sbin, instead of /usr/sbin.
libext2fs.texinfo:
Update version string to be 1.12
Makefile.in:
Fix bug in find script which made the exclusion list, where a '-' was
missing from an -name option.
ext2fs.h: Make ext2fs_get_mem take an unsigned argument.
fileio.c (ext2fs_file_get_size, ext2fs_file_set_size, ext2fs_file_get_fs):
New functions added.
bitops.c (ext2fs_warn_bitmap, ext2fs_warn_bitmap2): Don't call com_err
if OMIT_COM_ERR is defined.
Added definition of ext2fs_get_mem, ext2fs_free_mem, and
ext2fs_resize_mem in ext2fs.h, and changed all library routines to use
these wrapper functions.
ext2fs.h: Added function declarations and constants for bmap.c and
fileio.c.
ext2_err.et.in: Added new error messages EXT2_FILE_RO and
EXT2_ET_MAGIC_EXT2_FILE
Makefile.in: Added files bmap.c and fileio.c, and temporarily
commented out brel_ma.c and irel_ma.c
bmap.c: New file which maps a file's logical block number to its
physical block number.
fileio.c: New file which implements simple file reading and writing
primitives.
alloc.c (ext2fs_alloc_block): New function which allocates a block,
zeros it, and updates the filesystem accounting records appropriately.
Theodore Ts'o