KEYS: fix "ca_keys=" partial key matching

The call to asymmetric_key_hex_to_key_id() from ca_keys_setup()
silently fails with -ENOMEM.  Instead of dynamically allocating
memory from a __setup function, this patch defines a variable
and calls __asymmetric_key_hex_to_key_id(), a new helper function,
directly.

This bug was introduced by 'commit 46963b774d ("KEYS: Overhaul
key identification when searching for asymmetric keys")'.

Changelog:
- for clarification, rename hexlen to asciihexlen in
  asymmetric_key_hex_to_key_id()
- add size argument to __asymmetric_key_hex_to_key_id() - David Howells
- inline __asymmetric_key_hex_to_key_id() - David Howells
- remove duplicate strlen() calls

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.18
This commit is contained in:
Mimi Zohar 2015-02-11 07:33:34 -05:00
parent 7c51bb00c4
commit f2b3dee484
3 changed files with 35 additions and 11 deletions

View File

@ -11,6 +11,9 @@
extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);
extern int __asymmetric_key_hex_to_key_id(const char *id,
struct asymmetric_key_id *match_id,
size_t hexlen);
static inline
const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key)
{

View File

@ -104,6 +104,15 @@ static bool asymmetric_match_key_ids(
return false;
}
/* helper function can be called directly with pre-allocated memory */
inline int __asymmetric_key_hex_to_key_id(const char *id,
struct asymmetric_key_id *match_id,
size_t hexlen)
{
match_id->len = hexlen;
return hex2bin(match_id->data, id, hexlen);
}
/**
* asymmetric_key_hex_to_key_id - Convert a hex string into a key ID.
* @id: The ID as a hex string.
@ -111,21 +120,20 @@ static bool asymmetric_match_key_ids(
struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id)
{
struct asymmetric_key_id *match_id;
size_t hexlen;
size_t asciihexlen;
int ret;
if (!*id)
return ERR_PTR(-EINVAL);
hexlen = strlen(id);
if (hexlen & 1)
asciihexlen = strlen(id);
if (asciihexlen & 1)
return ERR_PTR(-EINVAL);
match_id = kmalloc(sizeof(struct asymmetric_key_id) + hexlen / 2,
match_id = kmalloc(sizeof(struct asymmetric_key_id) + asciihexlen / 2,
GFP_KERNEL);
if (!match_id)
return ERR_PTR(-ENOMEM);
match_id->len = hexlen / 2;
ret = hex2bin(match_id->data, id, hexlen / 2);
ret = __asymmetric_key_hex_to_key_id(id, match_id, asciihexlen / 2);
if (ret < 0) {
kfree(match_id);
return ERR_PTR(-EINVAL);

View File

@ -28,17 +28,30 @@ static bool use_builtin_keys;
static struct asymmetric_key_id *ca_keyid;
#ifndef MODULE
static struct {
struct asymmetric_key_id id;
unsigned char data[10];
} cakey;
static int __init ca_keys_setup(char *str)
{
if (!str) /* default system keyring */
return 1;
if (strncmp(str, "id:", 3) == 0) {
struct asymmetric_key_id *p;
p = asymmetric_key_hex_to_key_id(str + 3);
if (p == ERR_PTR(-EINVAL))
pr_err("Unparsable hex string in ca_keys\n");
else if (!IS_ERR(p))
struct asymmetric_key_id *p = &cakey.id;
size_t hexlen = (strlen(str) - 3) / 2;
int ret;
if (hexlen == 0 || hexlen > sizeof(cakey.data)) {
pr_err("Missing or invalid ca_keys id\n");
return 1;
}
ret = __asymmetric_key_hex_to_key_id(str + 3, p, hexlen);
if (ret < 0)
pr_err("Unparsable ca_keys id hex string\n");
else
ca_keyid = p; /* owner key 'id:xxxxxx' */
} else if (strcmp(str, "builtin") == 0) {
use_builtin_keys = true;