[PATCH 3.14 13/19] efi: Do variable name validation tests in utf8

Greg Kroah-Hartman
2016-03-14T18:00:56Z

From: Peter Jones <pjones@redhat.com>

commit 3dcb1f55dfc7631695e69df4a0d589ce5274bd07 upstream.

Actually translate from ucs2 to utf8 before doing the test, and then
test against our other utf8 data, instead of fudging it.

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

---
drivers/firmware/efi/efivars.c | 4 +-
drivers/firmware/efi/vars.c | 58 ++++++++++++++++++++++++-----------------
include/linux/efi.h | 6 ++--
3 files changed, 40 insertions(+), 28 deletions(-)

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

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

if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
- efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
+ efivar_validate(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
@@ -42,7 +42,7 @@ DECLARE_WORK(efivar_work, NULL);
EXPORT_SYMBOL_GPL(efivar_work);

static bool
-validate_device_path(struct efi_variable *var, int match, u8 *buffer,
+validate_device_path(efi_char16_t *var_name, int match, u8 *buffer,
unsigned long len)
{
struct efi_generic_dev_path *node;
@@ -75,7 +75,7 @@ validate_device_path(struct efi_variable
}

static bool
-validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
+validate_boot_order(efi_char16_t *var_name, int match, u8 *buffer,
unsigned long len)
{
/* An array of 16-bit integers */
@@ -86,18 +86,18 @@ validate_boot_order(struct efi_variable
}

static bool
-validate_load_option(struct efi_variable *var, int match, u8 *buffer,
+validate_load_option(efi_char16_t *var_name, int match, u8 *buffer,
unsigned long len)
{
u16 filepathlength;
int i, desclength = 0, namelen;

- namelen = ucs2_strnlen(var->VariableName, sizeof(var->VariableName));
+ namelen = ucs2_strnlen(var_name, EFI_VAR_NAME_LEN);

/* Either "Boot" or "Driver" followed by four digits of hex */
for (i = match; i < match+4; i++) {
- if (var->VariableName[i] > 127 ||
- hex_to_bin(var->VariableName[i] & 0xff) < 0)
+ if (var_name[i] > 127 ||
+ hex_to_bin(var_name[i] & 0xff) < 0)
return true;
}

@@ -132,12 +132,12 @@ validate_load_option(struct efi_variable
/*
* And, finally, check the filepath
*/
- return validate_device_path(var, match, buffer + desclength + 6,
+ return validate_device_path(var_name, match, buffer + desclength + 6,
filepathlength);
}

static bool
-validate_uint16(struct efi_variable *var, int match, u8 *buffer,
+validate_uint16(efi_char16_t *var_name, int match, u8 *buffer,
unsigned long len)
{
/* A single 16-bit integer */
@@ -148,7 +148,7 @@ validate_uint16(struct efi_variable *var
}

static bool
-validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
+validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer,
unsigned long len)
{
int i;
@@ -166,7 +166,7 @@ validate_ascii_string(struct efi_variabl

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

@@ -189,10 +189,19 @@ static const struct variable_validate va
};

bool
-efivar_validate(struct efi_variable *var, u8 *data, unsigned long len)
+efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long data_size)
{
int i;
- u16 *unicode_name = var->VariableName;
+ unsigned long utf8_size;
+ u8 *utf8_name;
+
+ utf8_size = ucs2_utf8size(var_name);
+ utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
+ if (!utf8_name)
+ return false;
+
+ ucs2_as_utf8(utf8_name, var_name, utf8_size);
+ utf8_name[utf8_size] = '\0';

for (i = 0; variable_validate[i].validate != NULL; i++) {
const char *name = variable_validate[i].name;
@@ -200,28 +209,29 @@ efivar_validate(struct efi_variable *var

for (match = 0; ; match++) {
char c = name[match];
- u16 u = unicode_name[match];
-
- /* All special variables are plain ascii */
- if (u > 127)
- return true;
+ char u = utf8_name[match];

/* Wildcard in the matching name means we've matched */
- if (c == '*')
- return variable_validate[i].validate(var,
- match, data, len);
+ if (c == '*') {
+ kfree(utf8_name);
+ return variable_validate[i].validate(var_name,
+ match, data, data_size);
+ }

/* Case sensitive match */
if (c != u)
break;

/* Reached the end of the string while matching */
- if (!c)
- return variable_validate[i].validate(var,
- match, data, len);
+ if (!c) {
+ kfree(utf8_name);
+ return variable_validate[i].validate(var_name,
+ match, data, data_size);
+ }
}
}

+ kfree(utf8_name);
return true;
}
EXPORT_SYMBOL_GPL(efivar_validate);
@@ -805,7 +815,7 @@ int efivar_entry_set_get_size(struct efi

*set = false;

- if (efivar_validate(&entry->var, data, *size) == false)
+ if (efivar_validate(name, data, *size) == false)
return -EINVAL;

/*
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -792,8 +792,10 @@ struct efivars {
* and we use a page for reading/writing.
*/

+#define EFI_VAR_NAME_LEN 1024
+
struct efi_variable {
- efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
+ efi_char16_t VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
efi_guid_t VendorGuid;
unsigned long DataSize;
__u8 Data[1024];
@@ -864,7 +866,7 @@ 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(struct efi_variable *var, u8 *data, unsigned long len);
+bool efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len);

extern struct work_struct efivar_work;
void efivar_run_worker(void);