Without any error propagated to the caller, make_file_path()
would then try to advance the invalid device path node with
GRUB_EFI_NEXT_DEVICE_PATH(), which would fail, returning a NULL
pointer that would subsequently be dereferenced. Hence, propagate
errors from copy_file_path().
Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Several places we take the length of a device path and subtract 4 from
it, without ever checking that it's >= 4. There are also cases where
this kind of malformation will result in unpredictable iteration,
including treating the length from one dp node as the type in the next
node. These are all errors, no matter where the data comes from.
This patch adds a checking macro, GRUB_EFI_DEVICE_PATH_VALID(), which
can be used in several places, and makes GRUB_EFI_NEXT_DEVICE_PATH()
return NULL and GRUB_EFI_END_ENTIRE_DEVICE_PATH() evaluate as true when
the length is too small. Additionally, it makes several places in the
code check for and return errors in these cases.
Signed-off-by: Peter Jones <pjones@redhat.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>
The address of fp->path_name could be unaligned since seeking into the
device path buffer for a given node could end in byte boundary.
The fix is using aligned buffer allocated by grub_malloc for receiving
the converted UTF16 string by grub_utf8_to_utf16 and also the processing
after. The resulting string then gets copied to fp->path_name.
[ 243s] ../../grub-core/loader/efi/chainloader.c: In function 'copy_file_path':
[ 243s] ../../grub-core/loader/efi/chainloader.c:136:32: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 243s] 136 | size = grub_utf8_to_utf16 (fp->path_name, len * GRUB_MAX_UTF16_PER_UTF8,
[ 243s] | ~~^~~~~~~~~~~
[ 243s] ../../grub-core/loader/efi/chainloader.c:138:12: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 243s] 138 | for (p = fp->path_name; p < fp->path_name + size; p++)
[ 243s] | ^~
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.
This is preparatory patch.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
EFI File Path Media Device Path is defined as NULL terminated string;
but chainloader built file paths without final NULL. This caused error
with Secure Boot and Linux Foundation PreLoader on Acer with InsydeH20 BIOS.
Apparently firmware failed verification with EFI_INVALID_PARAMETER which is
considered fatal error by PreLoader.
Reported and tested by Giovanni Santini <itachi.sama.amaterasu@gmail.com>
file_path to 0 for surety.
(grub_chainloader_boot): Set exit_data to NULL.
Unset the loader once done.
(grub_cmd_chainloader): Fix confusing error message if file is empty.
