It was possible to read OOB when an attribute had a size that exceeded
the allocated buffer. This resolves that by making sure all attributes
that get read are fully in the allocated space by implementing
a function to validate them.
Defining the offsets in include/grub/ntfs.h but they are only used in
the validation function and not across the rest of the NTFS code.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Right now to access the next attribute the code reads the length of the
current attribute and adds that to the current pointer. This is error
prone as bounds checking needs to be performed all over the place. So,
implement a helper and ensure its used across find_attr() and read_attr().
This commit does *not* implement full bounds checking. It is just the
preparation work for this to be added into the helper.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The end of the attribute buffer should be stored alongside the rest of
the attribute struct as right now it is not possible to implement bounds
checking when accessing attributes sequentially.
This is done via:
- updating init_attr() to set at->end and check is is not initially out of bounds,
- implementing checks as init_attr() had its type change in its callers,
- updating the value of at->end when needed.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When parsing NTFS file records the presence of the 0xFF marker indicates
the end of the attribute list. This value signifies that there are no
more attributes to process.
However, when the end marker is missing due to corrupted metadata the
loop continues to read beyond the attribute list resulting in out-of-bounds
reads and potentially entering an infinite loop.
This patch adds a check to provide a stop condition for the loop ensuring
it stops at the end of the attribute list or at the end of the Master File
Table. This guards against out-of-bounds reads and prevents infinite loops.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Move some calls used to access NTFS attribute header fields into
functions with human-readable names.
Suggested-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This fix introduces checks to ensure that an NTFS volume label is always
read from the corresponding file record segment.
The current NTFS code allows the volume label string to be read from an
arbitrary, attacker-chosen memory location. However, the bytes read are
always treated as UTF-16LE. So, the final string displayed is mostly
unreadable and it can't be easily converted back to raw bytes.
The lack of this check is a minor issue, likely not causing a significant
data leak.
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This fix introduces checks to ensure that bitmaps for directory indices
are never read beyond their actual sizes.
The lack of this check is a minor issue, likely not exploitable in any way.
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This fix introduces checks to ensure that index entries are never read
beyond the corresponding directory index.
The lack of this check is a minor issue, likely not exploitable in any way.
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When reading a file containing resident data, i.e., the file data is stored in
the $DATA attribute within the NTFS file record, not in external clusters,
there are no checks that this resident data actually fits the corresponding
file record segment.
When parsing a specially-crafted file system image, the current NTFS code will
read the file data from an arbitrary, attacker-chosen memory offset and of
arbitrary, attacker-chosen length.
This allows an attacker to display arbitrary chunks of memory, which could
contain sensitive information like password hashes or even plain-text,
obfuscated passwords from BS EFI variables.
This fix implements a check to ensure that resident data is read from the
corresponding file record segment only.
Fixes: CVE-2023-4693
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When parsing an extremely fragmented $MFT file, i.e., the file described
using the $ATTRIBUTE_LIST attribute, current NTFS code will reuse a buffer
containing bytes read from the underlying drive to store sector numbers,
which are consumed later to read data from these sectors into another buffer.
These sectors numbers, two 32-bit integers, are always stored at predefined
offsets, 0x10 and 0x14, relative to first byte of the selected entry within
the $ATTRIBUTE_LIST attribute. Usually, this won't cause any problem.
However, when parsing a specially-crafted file system image, this may cause
the NTFS code to write these integers beyond the buffer boundary, likely
causing the GRUB memory allocator to misbehave or fail. These integers contain
values which are controlled by on-disk structures of the NTFS file system.
Such modification and resulting misbehavior may touch a memory range not
assigned to the GRUB and owned by firmware or another EFI application/driver.
This fix introduces checks to ensure that these sector numbers are never
written beyond the boundary.
Fixes: CVE-2023-4692
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This modifies most of the places we do some form of:
X = malloc(Y * Z);
to use calloc(Y, Z) instead.
Among other issues, this fixes:
- allocation of integer overflow in grub_png_decode_image_header()
reported by Chris Coulson,
- allocation of integer overflow in luks_recover_key()
reported by Chris Coulson,
- allocation of integer overflow in grub_lvm_detect()
reported by Chris Coulson.
Fixes: CVE-2020-14308
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* include/grub/ntfs.h (grub_ntfscomp_func_t): Use appropriately sized
types.
* grub-core/fs/ntfs.c (grub_ntfs_read): Return correct -1 on error and
not 0.
* grub-core/fs/ntfscomp.c (read_block): Use appropriately-sized types.
Relax check for inline extents.
(ntfscomp): Return correct -1 on error and not 0.
* grub-core/fs/ntfs.c (list_file): Set symlink type when appropriate.
(symlink_descriptor): New struct.
(grub_ntfs_read_symlink): New function.
(grub_ntfs_iterate_dir): Use grub_ntfs_read_symlink.
(grub_ntfs_open): Likewise.
* grub-core/kern/misc.c (grub_divmod64_full): Renamed to ...
(grub_divmod64): ... this.
* include/grub/misc.h (grub_divmod64): Removed. All users switch to full
version.
* grub-core/fs/affs.c (grub_affs_time): New struct.
(grub_affs_file): New field mtime.
(grub_fshelp_node): Changed 'block' and 'parent' to more appropriate
type. Removed 'size'. New field 'di'. All users updated.
(grub_affs_mount): Simplify checsum checking.
(grub_affs_iterate_dir): New helper grub_affs_create_node.
(grub_affs_dir): Handle mtime.
* grub-core/fs/cpio.c (grub_cpio_find_file): Handle mtime.
(grub_cpio_dir): Likewise.
* grub-core/fs/hfs.c (grub_hfs_dirrec): New fields 'ctime' and 'mtime'.
(grub_hfs_filerec): New field mtime.
(grub_hfs_dir): Handle mtime.
(grub_hfs_mtime): New function.
(grub_hfs_fs): Register grub_hfs_mtime.
* grub-core/fs/iso9660.c (grub_iso9660_date2): New struct.
(grub_iso9660_dir): New field mtime.
(grub_fshelp_node): New field dirent.
(iso9660_to_unixtime): New function.
(iso9660_to_unixtime2): Likewise.
(grub_iso9660_read_symlink): Use node->dirent.
(grub_iso9660_iterate_dir): Likewise.
(grub_iso9660_dir): Set mtime.
(grub_iso9660_mtime): New function.
(grub_iso9660_fs): Register grub_iso9660_mtime.
* grub-core/fs/jfs.c (grub_jfs_time): New struct.
(grub_jfs_inode): New fields atime, ctime and mtime.
(grub_jfs_dir): Set mtime.
* grub-core/fs/minix.c (grub_minix_dir): Likewise.
* grub-core/fs/ntfs.c (list_file): Set mtime.
(grub_ntfs_dir): Likewise.
* grub-core/fs/reiserfs.c (grub_fshelp_node): New field 'mtime'.
(grub_reiserfs_iterate_dir): Set mtime.
(grub_reiserfs_dir): Likewise.
* grub-core/fs/sfs.c (grub_sfs_obj): New field mtime.
(grub_fshelp_node): Likewise.
(grub_sfs_iterate_dir): Set mtime.
(grub_sfs_dir): Likewise.
* grub-core/fs/udf.c (grub_udf_dir): Set mtime.
* grub-core/fs/xfs.c (grub_xfs_time): New struct.
(grub_xfs_inode): New fields atime, mtime, ctime.
(grub_xfs_dir): Set mtime.
* include/grub/datetime.h (grub_datetime2unixtime): New function.
* include/grub/hfs.h (grub_hfs_sblock): New fields ctime and mtime.
* include/grub/ntfs.h (grub_fshelp_node): New field mtime.
Support UDF symlinks.
* grub-core/fs/udf.c (grub_udf_iterate_dir): Handle symlinks.
(grub_ufs_read_symlink): New function. All users updated.
Check amiga partmap checksum.
* grub-core/partmap/amiga.c (grub_amiga_rdsk): Pad to 128 bytes.
(grub_amiga_partition): Likewise.
(amiga_partition_map_checksum): New function.
(amiga_partition_map_iterate): Check checksum.
