efi/chainloader: Propagate errors from copy_file_path()

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>
This commit is contained in:
Daniel Kiper 2020-07-29 13:38:31 +02:00
parent d2cf823d0e
commit 098058752e

View file

@ -106,7 +106,7 @@ grub_chainloader_boot (void)
return grub_errno;
}
static void
static grub_err_t
copy_file_path (grub_efi_file_path_device_path_t *fp,
const char *str, grub_efi_uint16_t len)
{
@ -118,7 +118,7 @@ copy_file_path (grub_efi_file_path_device_path_t *fp,
path_name = grub_calloc (len, GRUB_MAX_UTF16_PER_UTF8 * sizeof (*path_name));
if (!path_name)
return;
return grub_error (GRUB_ERR_OUT_OF_MEMORY, "failed to allocate path buffer");
size = grub_utf8_to_utf16 (path_name, len * GRUB_MAX_UTF16_PER_UTF8,
(const grub_uint8_t *) str, len, 0);
@ -131,6 +131,7 @@ copy_file_path (grub_efi_file_path_device_path_t *fp,
fp->path_name[size++] = '\0';
fp->header.length = size * sizeof (grub_efi_char16_t) + sizeof (*fp);
grub_free (path_name);
return GRUB_ERR_NONE;
}
static grub_efi_device_path_t *
@ -189,13 +190,19 @@ make_file_path (grub_efi_device_path_t *dp, const char *filename)
d = (grub_efi_device_path_t *) ((char *) file_path
+ ((char *) d - (char *) dp));
grub_efi_print_device_path (d);
copy_file_path ((grub_efi_file_path_device_path_t *) d,
dir_start, dir_end - dir_start);
if (copy_file_path ((grub_efi_file_path_device_path_t *) d,
dir_start, dir_end - dir_start) != GRUB_ERR_NONE)
{
fail:
grub_free (file_path);
return 0;
}
/* Fill the file path for the file. */
d = GRUB_EFI_NEXT_DEVICE_PATH (d);
copy_file_path ((grub_efi_file_path_device_path_t *) d,
dir_end + 1, grub_strlen (dir_end + 1));
if (copy_file_path ((grub_efi_file_path_device_path_t *) d,
dir_end + 1, grub_strlen (dir_end + 1)) != GRUB_ERR_NONE)
goto fail;
/* Fill the end of device path nodes. */
d = GRUB_EFI_NEXT_DEVICE_PATH (d);