[PATCH 3.14 14/19] efi: Make our variable validation list include the guid

Greg Kroah-Hartman
2016-03-14T18:00:52Z

From: Peter Jones <pjones@redhat.com>

commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream.

All the variables in this list so far are defined to be in the global
namespace in the UEFI spec, so this just further ensures we're
validating the variables we think we are.

Including the guid for entries will become more important in future
patches when we decide whether or not to allow deletion of variables
based on presence in this list.

Signed-off-by: Peter Jones <pjones@redhat.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/firmware/efi/efivars.c | 6 +++-
drivers/firmware/efi/vars.c | 52 ++++++++++++++++++++++++++---------------
include/linux/efi.h | 3 +-
3 files changed, 39 insertions(+), 22 deletions(-)

--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -219,7 +219,8 @@ efivar_store_raw(struct efivar_entry *en
}

if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
- efivar_validate(new_var->VariableName, new_var->Data, new_var->DataSize) == false) {
+ efivar_validate(new_var->VendorGuid, new_var->VariableName,
+ new_var->Data, new_var->DataSize) == false) {
printk(KERN_ERR "efivars: Malformed variable content\n");
return -EINVAL;
}
@@ -334,7 +335,8 @@ static ssize_t efivar_create(struct file
return -EACCES;

if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
- efivar_validate(new_var->VariableName, new_var->Data, new_var->DataSize) == false) {
+ efivar_validate(new_var->VendorGuid, new_var->VariableName,
+ new_var->Data, new_var->DataSize) == false) {
printk(KERN_ERR "efivars: Malformed variable content\n");
return -EINVAL;
}
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -165,31 +165,42 @@ validate_ascii_string(efi_char16_t *var_
}

struct variable_validate {
+ efi_guid_t vendor;
char *name;
bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
unsigned long len);
};

+/*
+ * This is the list of variables we need to validate.
+ *
+ * If it has a validate() method that's not NULL, it'll go into the
+ * validation routine. If not, it is assumed valid.
+ *
+ * Note that it's sorted by {vendor,name}, but globbed names must come after
+ * any other name with the same prefix.
+ */
static const struct variable_validate variable_validate[] = {
- { "BootNext", validate_uint16 },
- { "BootOrder", validate_boot_order },
- { "DriverOrder", validate_boot_order },
- { "Boot*", validate_load_option },
- { "Driver*", validate_load_option },
- { "ConIn", validate_device_path },
- { "ConInDev", validate_device_path },
- { "ConOut", validate_device_path },
- { "ConOutDev", validate_device_path },
- { "ErrOut", validate_device_path },
- { "ErrOutDev", validate_device_path },
- { "Timeout", validate_uint16 },
- { "Lang", validate_ascii_string },
- { "PlatformLang", validate_ascii_string },
- { "", NULL },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
+ { NULL_GUID, "", NULL },
};

bool
-efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long data_size)
+efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+ unsigned long data_size)
{
int i;
unsigned long utf8_size;
@@ -203,9 +214,12 @@ efivar_validate(efi_char16_t *var_name,
ucs2_as_utf8(utf8_name, var_name, utf8_size);
utf8_name[utf8_size] = '\0';

- for (i = 0; variable_validate[i].validate != NULL; i++) {
+ for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
const char *name = variable_validate[i].name;
- int match;
+ int match = 0;
+
+ if (efi_guidcmp(vendor, variable_validate[i].vendor))
+ continue;

for (match = 0; ; match++) {
char c = name[match];
@@ -815,7 +829,7 @@ int efivar_entry_set_get_size(struct efi

*set = false;

- if (efivar_validate(name, data, *size) == false)
+ if (efivar_validate(*vendor, name, data, *size) == false)
return -EINVAL;

/*
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -866,7 +866,8 @@ int efivar_entry_iter(int (*func)(struct
struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
struct list_head *head, bool remove);

-bool efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len);
+bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+ unsigned long data_size);

extern struct work_struct efivar_work;
void efivar_run_worker(void);