diff options
Diffstat (limited to 'drivers/firmware/efivars.c')
| -rw-r--r-- | drivers/firmware/efivars.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 6607daf5a08d..1e9d9b9d7a12 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1705,6 +1705,31 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) return found; } +/* + * Returns the size of variable_name, in bytes, including the + * terminating NULL character, or variable_name_size if no NULL + * character is found among the first variable_name_size bytes. + */ +static unsigned long var_name_strnsize(efi_char16_t *variable_name, + unsigned long variable_name_size) +{ + unsigned long len; + efi_char16_t c; + + /* + * The variable name is, by definition, a NULL-terminated + * string, so make absolutely sure that variable_name_size is + * the value we expect it to be. If not, return the real size. + */ + for (len = 2; len <= variable_name_size; len += sizeof(c)) { + c = variable_name[(len / sizeof(c)) - 1]; + if (!c) + break; + } + + return min(len, variable_name_size); +} + static void efivar_update_sysfs_entries(struct work_struct *work) { struct efivars *efivars = &__efivars; @@ -1745,10 +1770,13 @@ static void efivar_update_sysfs_entries(struct work_struct *work) if (!found) { kfree(variable_name); break; - } else + } else { + variable_name_size = var_name_strnsize(variable_name, + variable_name_size); efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, &vendor); + } } } @@ -1995,6 +2023,8 @@ int register_efivars(struct efivars *efivars, &vendor_guid); switch (status) { case EFI_SUCCESS: + variable_name_size = var_name_strnsize(variable_name, + variable_name_size); efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, |