diff options
| -rw-r--r-- | drivers/firmware/efivars.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index bfd8f4392492..9a1968e500f1 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -943,6 +943,31 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, } /* + * 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); +} + +/* * Let's not leave out systab information that snuck into * the efivars driver */ @@ -1169,6 +1194,8 @@ 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, |