KEYS: trusted: fix TPM trusted keys for generic framework

The generic framework patch broke the current TPM trusted keys because
it doesn't correctly remove the values consumed by the generic parser
before passing them on to the implementation specific parser.  Fix
this by having the generic parser return the string minus the consumed
tokens.

Additionally, there may be no tokens left for the implementation
specific parser, so make it handle the NULL case correctly and finally
fix a TPM 1.2 specific check for no keyhandle.

Fixes: 5d0682be ("KEYS: trusted: Add generic trusted keys framework")
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

security/keys/trusted-keys/trusted_core.c

@@ -62,7 +62,7 @@ static const match_table_t key_tokens = {
  *
  * On success returns 0, otherwise -EINVAL.
  */
-static int datablob_parse(char *datablob, struct trusted_key_payload *p)
+static int datablob_parse(char **datablob, struct trusted_key_payload *p)
 {
 	substring_t args[MAX_OPT_ARGS];
 	long keylen;
@@ -71,14 +71,14 @@ static int datablob_parse(char *datablob, struct trusted_key_payload *p)
 	char *c;
 
 	/* main command */
-	c = strsep(&datablob, " \t");
+	c = strsep(datablob, " \t");
 	if (!c)
 		return -EINVAL;
 	key_cmd = match_token(c, key_tokens, args);
 	switch (key_cmd) {
 	case Opt_new:
 		/* first argument is key size */
-		c = strsep(&datablob, " \t");
+		c = strsep(datablob, " \t");
 		if (!c)
 			return -EINVAL;
 		ret = kstrtol(c, 10, &keylen);
@@ -89,7 +89,7 @@ static int datablob_parse(char *datablob, struct trusted_key_payload *p)
 		break;
 	case Opt_load:
 		/* first argument is sealed blob */
-		c = strsep(&datablob, " \t");
+		c = strsep(datablob, " \t");
 		if (!c)
 			return -EINVAL;
 		p->blob_len = strlen(c) / 2;
@@ -140,7 +140,7 @@ static int trusted_instantiate(struct key *key,
 {
 	struct trusted_key_payload *payload = NULL;
 	size_t datalen = prep->datalen;
-	char *datablob;
+	char *datablob, *orig_datablob;
 	int ret = 0;
 	int key_cmd;
 	size_t key_len;
@@ -148,7 +148,7 @@ static int trusted_instantiate(struct key *key,
 	if (datalen <= 0 || datalen > 32767 || !prep->data)
 		return -EINVAL;
 
-	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
 	if (!datablob)
 		return -ENOMEM;
 	memcpy(datablob, prep->data, datalen);
@@ -160,7 +160,7 @@ static int trusted_instantiate(struct key *key,
 		goto out;
 	}
 
-	key_cmd = datablob_parse(datablob, payload);
+	key_cmd = datablob_parse(&datablob, payload);
 	if (key_cmd < 0) {
 		ret = key_cmd;
 		goto out;
@@ -196,7 +196,7 @@ static int trusted_instantiate(struct key *key,
 		ret = -EINVAL;
 	}
 out:
-	kfree_sensitive(datablob);
+	kfree_sensitive(orig_datablob);
 	if (!ret)
 		rcu_assign_keypointer(key, payload);
 	else
@@ -220,7 +220,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
 	struct trusted_key_payload *p;
 	struct trusted_key_payload *new_p;
 	size_t datalen = prep->datalen;
-	char *datablob;
+	char *datablob, *orig_datablob;
 	int ret = 0;
 
 	if (key_is_negative(key))
@@ -231,7 +231,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
 	if (datalen <= 0 || datalen > 32767 || !prep->data)
 		return -EINVAL;
 
-	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
 	if (!datablob)
 		return -ENOMEM;
 
@@ -243,7 +243,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
 
 	memcpy(datablob, prep->data, datalen);
 	datablob[datalen] = '\0';
-	ret = datablob_parse(datablob, new_p);
+	ret = datablob_parse(&datablob, new_p);
 	if (ret != Opt_update) {
 		ret = -EINVAL;
 		kfree_sensitive(new_p);
@@ -267,7 +267,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
 	rcu_assign_keypointer(key, new_p);
 	call_rcu(&p->rcu, trusted_rcu_free);
 out:
-	kfree_sensitive(datablob);
+	kfree_sensitive(orig_datablob);
 	return ret;
 }
 

security/keys/trusted-keys/trusted_tpm1.c

@@ -747,6 +747,9 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 
 	opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 
+	if (!c)
+		return 0;
+
 	while ((p = strsep(&c, " \t"))) {
 		if (*p == '\0' || *p == ' ' || *p == '\t')
 			continue;
@@ -944,7 +947,7 @@ static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
 		goto out;
 	dump_options(options);
 
-	if (!options->keyhandle) {
+	if (!options->keyhandle && !tpm2) {
 		ret = -EINVAL;
 		goto out;
 	}