Re: [PATCH v5] keys/trusted_keys: move TPM-specific fields into struct trusted_key_tpm

Hi Jarkko,

On 9/1/26 10:31 PM, Jarkko Sakkinen wrote:

On Tue, Sep 01, 2026 at 09:11:32PM +0530, Srish Srinivasan wrote:

quoted

The trusted_key_options struct contains TPM-specific fields (keyhandle,
keyauth, blobauth_len, blobauth, pcrinfo_len, pcrinfo, pcrlock, hash,
policydigest_len, policydigest, and policyhandle). This leads to the
accumulation of backend-specific fields in the generic options structure.

Define struct trusted_key_tpm and move the TPM-specific fields there. Store
a pointer to it in the private member of struct trusted_key_options.

No functional change intended.

Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
Changelog:

  v5:
   - Rename struct trusted_tpm_options to struct trusted_key_tpm, as suggested
     by Jarkko.

  v4:
   - Rebased onto mainline after tpm-buf memory-safe allocation changes were
     merged
   - Resolved the resulting merge conflicts

  v3:
   - Exclude the preparatory clean up patch as the problem has been addressed
     in commit 9ec4175a30eb ("KEYS: trusted: Debugging as a feature")

  v2:
   - Exclude the bug-fix patch as it has already been applied to 6.19-rc7
   - Rename instances of trusted_tpm_options from tpm_opts to private
   - Use pr_debug and KERN_DEBUG for logging debug messages (preparatory clean
     up patch)
   - Address other minor comments from Jarkko

  include/keys/trusted-type.h               | 11 ---
  include/keys/trusted_tpm.h                | 14 ++++
  security/keys/trusted-keys/trusted_tpm1.c | 96 ++++++++++++++---------
  security/keys/trusted-keys/trusted_tpm2.c | 50 ++++++------
  4 files changed, 102 insertions(+), 69 deletions(-)

diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index 9f9940482da4..3db61b57cf73 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h

@@ -39,17 +39,6 @@ struct trusted_key_payload {
  
  struct trusted_key_options {
  	uint16_t keytype;
-	uint32_t keyhandle;
-	unsigned char keyauth[TPM_DIGEST_SIZE];
-	uint32_t blobauth_len;
-	unsigned char blobauth[TPM_DIGEST_SIZE];
-	uint32_t pcrinfo_len;
-	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
-	int pcrlock;
-	uint32_t hash;
-	uint32_t policydigest_len;
-	unsigned char policydigest[MAX_DIGEST_SIZE];
-	uint32_t policyhandle;
  	void *private;
  };
  

diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h
index 3a0fa3bc8454..dafbd4a84ddd 100644
--- a/include/keys/trusted_tpm.h
+++ b/include/keys/trusted_tpm.h

@@ -6,6 +6,20 @@
  
  extern struct trusted_key_ops trusted_key_tpm_ops;
  
+struct trusted_key_tpm {
+	uint32_t keyhandle;
+	unsigned char keyauth[TPM_DIGEST_SIZE];
+	uint32_t blobauth_len;
+	unsigned char blobauth[TPM_DIGEST_SIZE];
+	uint32_t pcrinfo_len;
+	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
+	int pcrlock;
+	uint32_t hash;
+	uint32_t policydigest_len;
+	unsigned char policydigest[MAX_DIGEST_SIZE];
+	uint32_t policyhandle;
+};
+
  int tpm2_seal_trusted(struct tpm_chip *chip,
  		      struct trusted_key_payload *payload,
  		      struct trusted_key_options *options);

diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
index bf0bf7f36970..d396f4267180 100644
--- a/security/keys/trusted-keys/trusted_tpm1.c
+++ b/security/keys/trusted-keys/trusted_tpm1.c

@@ -48,15 +48,17 @@ enum {
  #ifdef CONFIG_TRUSTED_KEYS_DEBUG
  static inline void dump_options(struct trusted_key_options *o)
  {
+	struct trusted_key_tpm *private = o->private;
+
  	if (!trusted_debug)
  		return;
  
  	pr_debug("sealing key type %d\n", o->keytype);
-	pr_debug("sealing key handle %0X\n", o->keyhandle);
-	pr_debug("pcrlock %d\n", o->pcrlock);
-	pr_debug("pcrinfo %d\n", o->pcrinfo_len);
+	pr_debug("sealing key handle %0X\n", private->keyhandle);
+	pr_debug("pcrlock %d\n", private->pcrlock);
+	pr_debug("pcrinfo %d\n", private->pcrinfo_len);
  	print_hex_dump_debug("pcrinfo ", DUMP_PREFIX_NONE,
-			     16, 1, o->pcrinfo, o->pcrinfo_len, 0);
+			     16, 1, private->pcrinfo, private->pcrinfo_len, 0);
  }
  
  static inline void dump_sess(struct osapsess *s)

@@ -626,6 +628,7 @@ static int tpm_unseal(struct tpm_buf *tb,
  static int key_seal(struct trusted_key_payload *p,
  		    struct trusted_key_options *o)
  {
+	struct trusted_key_tpm *private = o->private;
  	int ret;
  
  	struct tpm_buf *tb __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);

@@ -637,9 +640,10 @@ static int key_seal(struct trusted_key_payload *p,
  	/* include migratable flag at end of sealed key */
  	p->key[p->key_len] = p->migratable;
  
-	ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
+	ret = tpm_seal(tb, o->keytype, private->keyhandle, private->keyauth,
  		       p->key, p->key_len + 1, p->blob, &p->blob_len,
-		       o->blobauth, o->pcrinfo, o->pcrinfo_len);
+		       private->blobauth, private->pcrinfo,
+		       private->pcrinfo_len);
  	if (ret < 0)
  		pr_info("srkseal failed (%d)\n", ret);
  

@@ -652,6 +656,7 @@ static int key_seal(struct trusted_key_payload *p,
  static int key_unseal(struct trusted_key_payload *p,
  		      struct trusted_key_options *o)
  {
+	struct trusted_key_tpm *private = o->private;
  	int ret;
  
  	struct tpm_buf *tb __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);

@@ -660,8 +665,8 @@ static int key_unseal(struct trusted_key_payload *p,
  
  	tpm_buf_init(tb, TPM_BUFSIZE);
  
-	ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
-			 o->blobauth, p->key, &p->key_len);
+	ret = tpm_unseal(tb, private->keyhandle, private->keyauth, p->blob,
+			 p->blob_len, private->blobauth, p->key, &p->key_len);
  	if (ret < 0)
  		pr_info("srkunseal failed (%d)\n", ret);
  	else

@@ -697,6 +702,7 @@ static const match_table_t key_tokens = {
  static int getoptions(char *c, struct trusted_key_payload *pay,
  		      struct trusted_key_options *opt)
  {
+	struct trusted_key_tpm *private = opt->private;
  	substring_t args[MAX_OPT_ARGS];
  	char *p = c;
  	int token;

@@ -712,7 +718,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  	if (tpm2 < 0)
  		return tpm2;
  
-	opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
+	private->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
  
  	if (!c)
  		return 0;

@@ -726,11 +732,11 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  
  		switch (token) {
  		case Opt_pcrinfo:
-			opt->pcrinfo_len = strlen(args[0].from) / 2;
-			if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
+			private->pcrinfo_len = strlen(args[0].from) / 2;
+			if (private->pcrinfo_len > MAX_PCRINFO_SIZE)
  				return -EINVAL;
-			res = hex2bin(opt->pcrinfo, args[0].from,
-				      opt->pcrinfo_len);
+			res = hex2bin(private->pcrinfo, args[0].from,
+				      private->pcrinfo_len);
  			if (res < 0)
  				return -EINVAL;
  			break;

@@ -739,12 +745,12 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  			if (res < 0)
  				return -EINVAL;
  			opt->keytype = SEAL_keytype;
-			opt->keyhandle = handle;
+			private->keyhandle = handle;
  			break;
  		case Opt_keyauth:
  			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
  				return -EINVAL;
-			res = hex2bin(opt->keyauth, args[0].from,
+			res = hex2bin(private->keyauth, args[0].from,
  				      SHA1_DIGEST_SIZE);
  			if (res < 0)
  				return -EINVAL;

@@ -755,21 +761,23 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  			 * hex strings.  TPM 2.0 authorizations are simple
  			 * passwords (although it can take a hash as well)
  			 */
-			opt->blobauth_len = strlen(args[0].from);
+			private->blobauth_len = strlen(args[0].from);
  
-			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
-				res = hex2bin(opt->blobauth, args[0].from,
+			if (private->blobauth_len == 2 * TPM_DIGEST_SIZE) {
+				res = hex2bin(private->blobauth, args[0].from,
  					      TPM_DIGEST_SIZE);
  				if (res < 0)
  					return -EINVAL;
  
-				opt->blobauth_len = TPM_DIGEST_SIZE;
+				private->blobauth_len = TPM_DIGEST_SIZE;
  				break;
  			}
  
-			if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
-				memcpy(opt->blobauth, args[0].from,
-				       opt->blobauth_len);
+			if (tpm2 &&
+			    private->blobauth_len <=
+			    sizeof(private->blobauth)) {
+				memcpy(private->blobauth, args[0].from,
+				       private->blobauth_len);
  				break;
  			}
  

@@ -787,14 +795,14 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  			res = kstrtoul(args[0].from, 10, &lock);
  			if (res < 0)
  				return -EINVAL;
-			opt->pcrlock = lock;
+			private->pcrlock = lock;
  			break;
  		case Opt_hash:
  			if (test_bit(Opt_policydigest, &token_mask))
  				return -EINVAL;
  			for (i = 0; i < HASH_ALGO__LAST; i++) {
  				if (!strcmp(args[0].from, hash_algo_name[i])) {
-					opt->hash = i;
+					private->hash = i;
  					break;
  				}
  			}

@@ -806,14 +814,14 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  			}
  			break;
  		case Opt_policydigest:
-			digest_len = hash_digest_size[opt->hash];
+			digest_len = hash_digest_size[private->hash];
  			if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
  				return -EINVAL;
-			res = hex2bin(opt->policydigest, args[0].from,
+			res = hex2bin(private->policydigest, args[0].from,
  				      digest_len);
  			if (res < 0)
  				return -EINVAL;
-			opt->policydigest_len = digest_len;
+			private->policydigest_len = digest_len;
  			break;
  		case Opt_policyhandle:
  			if (!tpm2)

@@ -821,7 +829,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  			res = kstrtoul(args[0].from, 16, &handle);
  			if (res < 0)
  				return -EINVAL;
-			opt->policyhandle = handle;
+			private->policyhandle = handle;
  			break;
  		default:
  			return -EINVAL;

@@ -832,6 +840,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
  
  static struct trusted_key_options *trusted_options_alloc(void)
  {
+	struct trusted_key_tpm *private;
  	struct trusted_key_options *options;
  	int tpm2;
  

@@ -844,14 +853,22 @@ static struct trusted_key_options *trusted_options_alloc(void)
  		/* set any non-zero defaults */
  		options->keytype = SRK_keytype;
  
-		if (!tpm2)
-			options->keyhandle = SRKHANDLE;
+		private = kzalloc_obj(*private);
+		if (!private) {
+			kfree_sensitive(options);
+			options = NULL;
+		} else {
+			if (!tpm2)
+				private->keyhandle = SRKHANDLE;
+			options->private = private;
+		}
  	}
  	return options;
  }
  
  static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
  {
+	struct trusted_key_tpm *private = NULL;
  	struct trusted_key_options *options = NULL;

It would be leaner if you did:

	struct trusted_key_options *options __free(kfree_sensitive) = NULL;

Then you can just return instead of jumping to "out".

Applies also to trusted_tpm_unseal at least.

Thanks for bringing this up.
Yup, I have made the required changes and posted v6.

Link to v6: https://lore.kernel.org/all/20260902103120.222326-1-ssrish@linux.ibm.com/ (local)

quoted

  	int ret = 0;
  	int tpm2;

@@ -869,7 +886,8 @@ static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
  		goto out;
  	dump_options(options);
  
-	if (!options->keyhandle && !tpm2) {
+	private = options->private;
+	if (!private->keyhandle && !tpm2) {
  		ret = -EINVAL;
  		goto out;
  	}

@@ -883,20 +901,23 @@ static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
  		goto out;
  	}
  
-	if (options->pcrlock) {
-		ret = pcrlock(options->pcrlock);
+	if (private->pcrlock) {
+		ret = pcrlock(private->pcrlock);
  		if (ret < 0) {
  			pr_info("pcrlock failed (%d)\n", ret);
  			goto out;
  		}
  	}
  out:
+	if (options)
+		kfree_sensitive(options->private);
  	kfree_sensitive(options);
  	return ret;
  }
  
  static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
  {
+	struct trusted_key_tpm *private = NULL;
  	struct trusted_key_options *options = NULL;
  	int ret = 0;
  	int tpm2;

@@ -914,7 +935,8 @@ static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
  		goto out;
  	dump_options(options);
  
-	if (!options->keyhandle && !tpm2) {
+	private = options->private;
+	if (!private->keyhandle && !tpm2) {
  		ret = -EINVAL;
  		goto out;
  	}

@@ -926,14 +948,16 @@ static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
  	if (ret < 0)
  		pr_info("key_unseal failed (%d)\n", ret);
  
-	if (options->pcrlock) {
-		ret = pcrlock(options->pcrlock);
+	if (private->pcrlock) {
+		ret = pcrlock(private->pcrlock);
  		if (ret < 0) {
  			pr_info("pcrlock failed (%d)\n", ret);
  			goto out;
  		}
  	}
  out:
+	if (options)
+		kfree_sensitive(options->private);
  	kfree_sensitive(options);
  	return ret;
  }

diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 67225dd562a9..29da1a3328ef 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c

@@ -23,6 +23,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
  			   struct trusted_key_options *options,
  			   u8 *src, u32 len)
  {
+	struct trusted_key_tpm *private = options->private;
  	const int SCRATCH_SIZE = PAGE_SIZE;
  	u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
  	u8 *work = scratch, *work1;

@@ -45,7 +46,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
  	work = asn1_encode_oid(work, end_work, tpm2key_oid,
  			       asn1_oid_len(tpm2key_oid));
  
-	if (options->blobauth_len == 0) {
+	if (private->blobauth_len == 0) {
  		unsigned char bool[3], *w = bool;
  		/* tag 0 is emptyAuth */
  		w = asn1_encode_boolean(w, w + sizeof(bool), true);

@@ -68,7 +69,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
  		goto err;
  	}
  
-	work = asn1_encode_integer(work, end_work, options->keyhandle);
+	work = asn1_encode_integer(work, end_work, private->keyhandle);
  	work = asn1_encode_octet_string(work, end_work, pub, pub_len);
  	work = asn1_encode_octet_string(work, end_work, priv, priv_len);
  

@@ -101,6 +102,7 @@ static int tpm2_key_decode(struct trusted_key_payload *payload,
  			   struct trusted_key_options *options,
  			   u8 **buf)
  {
+	struct trusted_key_tpm *private = options->private;
  	int ret;
  	struct tpm2_key_context ctx;
  	u8 *blob;

@@ -120,7 +122,7 @@ static int tpm2_key_decode(struct trusted_key_payload *payload,
  		return -ENOMEM;
  
  	*buf = blob;
-	options->keyhandle = ctx.parent;
+	private->keyhandle = ctx.parent;
  
  	memcpy(blob, ctx.priv, ctx.priv_len);
  	blob += ctx.priv_len;

@@ -232,6 +234,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
  		      struct trusted_key_payload *payload,
  		      struct trusted_key_options *options)
  {
+	struct trusted_key_tpm *private = options->private;
  	off_t offset = TPM_HEADER_SIZE;
  	struct tpm_buf *buf __free(kfree) = NULL;
  	struct tpm_buf *sized __free(kfree) = NULL;

@@ -240,11 +243,11 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
  	u32 flags;
  	int rc;
  
-	hash = tpm2_find_hash_alg(options->hash);
+	hash = tpm2_find_hash_alg(private->hash);
  	if (hash < 0)
  		return hash;
  
-	if (!options->keyhandle)
+	if (!private->keyhandle)
  		return -EINVAL;
  
  	rc = tpm_try_get_ops(chip);

@@ -274,18 +277,18 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
  
  	tpm_buf_init_sized(sized, TPM_BUFSIZE);
  
-	rc = tpm_buf_append_name(chip, buf, options->keyhandle, NULL);
+	rc = tpm_buf_append_name(chip, buf, private->keyhandle, NULL);
  	if (rc)
  		goto out;
  
  	tpm_buf_append_hmac_session(chip, buf, TPM2_SA_DECRYPT,
-				    options->keyauth, TPM_DIGEST_SIZE);
+				    private->keyauth, TPM_DIGEST_SIZE);
  
  	/* sensitive */
-	tpm_buf_append_u16(sized, options->blobauth_len);
+	tpm_buf_append_u16(sized, private->blobauth_len);
  
-	if (options->blobauth_len)
-		tpm_buf_append(sized, options->blobauth, options->blobauth_len);
+	if (private->blobauth_len)
+		tpm_buf_append(sized, private->blobauth, private->blobauth_len);
  
  	tpm_buf_append_u16(sized, payload->key_len);
  	tpm_buf_append(sized, payload->key, payload->key_len);

@@ -298,14 +301,15 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
  
  	/* key properties */
  	flags = 0;
-	flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH;
+	flags |= private->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH;
  	flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT);
  	tpm_buf_append_u32(sized, flags);
  
  	/* policy */
-	tpm_buf_append_u16(sized, options->policydigest_len);
-	if (options->policydigest_len)
-		tpm_buf_append(sized, options->policydigest, options->policydigest_len);
+	tpm_buf_append_u16(sized, private->policydigest_len);
+	if (private->policydigest_len)
+		tpm_buf_append(sized, private->policydigest,
+			       private->policydigest_len);
  
  	/* public parameters */
  	tpm_buf_append_u16(sized, TPM_ALG_NULL);

@@ -376,6 +380,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
  			 u32 *blob_handle)
  {
  	u8 *blob_ref __free(kfree) = NULL;
+	struct trusted_key_tpm *private = options->private;
  	struct tpm_buf *buf __free(kfree) = NULL;
  	unsigned int private_len;
  	unsigned int public_len;

@@ -395,7 +400,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
  	}
  
  	/* new format carries keyhandle but old format doesn't */
-	if (!options->keyhandle)
+	if (!private->keyhandle)
  		return -EINVAL;
  
  	/* must be big enough for at least the two be16 size counts */

@@ -439,11 +444,11 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
  	tpm_buf_init(buf, TPM_BUFSIZE);
  	tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
  
-	rc = tpm_buf_append_name(chip, buf, options->keyhandle, NULL);
+	rc = tpm_buf_append_name(chip, buf, private->keyhandle, NULL);
  	if (rc)
  		return rc;
  
-	tpm_buf_append_hmac_session(chip, buf, 0, options->keyauth,
+	tpm_buf_append_hmac_session(chip, buf, 0, private->keyauth,
  				    TPM_DIGEST_SIZE);
  
  	tpm_buf_append(buf, blob, blob_len);

@@ -483,6 +488,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
  			   struct trusted_key_options *options,
  			   u32 blob_handle)
  {
+	struct trusted_key_tpm *private = options->private;
  	struct tpm_header *head;
  	struct tpm_buf *buf __free(kfree) = NULL;
  	u16 data_len;

@@ -507,10 +513,10 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
  	if (rc)
  		return rc;
  
-	if (!options->policyhandle) {
+	if (!private->policyhandle) {
  		tpm_buf_append_hmac_session(chip, buf, TPM2_SA_ENCRYPT,
-					    options->blobauth,
-					    options->blobauth_len);
+					    private->blobauth,
+					    private->blobauth_len);
  	} else {
  		/*
  		 * FIXME: The policy session was generated outside the

@@ -523,9 +529,9 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
  		 * could repeat our actions with the exfiltrated
  		 * password.
  		 */
-		tpm2_buf_append_auth(buf, options->policyhandle,
+		tpm2_buf_append_auth(buf, private->policyhandle,
  				     NULL /* nonce */, 0, 0,
-				     options->blobauth, options->blobauth_len);
+				     private->blobauth, private->blobauth_len);
  		if (tpm2_chip_auth(chip)) {
  			tpm_buf_append_hmac_session(chip, buf, TPM2_SA_ENCRYPT,
  						    NULL, 0);

-- 
2.53.0

BR, Jarkko

Thanks,
Srish.