[PATCH 3/3] tpm-buf: Implement managed allocations
Jarkko Sakkinen
jarkko at kernel.org
Sat Dec 6 17:00:46 UTC 2025
On Sat, Dec 06, 2025 at 01:31:10PM +0200, Jarkko Sakkinen wrote:
> From: Jarkko Sakkinen <jarkko.sakkinen at opinsys.com>
>
> Decouple kzalloc from buffer creation, so that a managed allocation can be
> used:
>
> struct tpm_buf *buf __free(kfree) buf = kzalloc(TPM_BUFSIZE,
> GFP_KERNEL);
> if (!buf)
> return -ENOMEM;
>
> tpm_buf_init(buf, TPM_BUFSIZE);
>
> Alternatively, stack allocations are also possible:
>
> u8 buf_data[512];
> struct tpm_buf *buf = (struct tpm_buf *)buf_data;
> tpm_buf_init(buf, sizeof(buf_data));
>
> This is achieved by embedding buffer's header inside the allocated blob,
> instead of having an outer wrapper.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen at opinsys.com>
> Reviewed-by: Stefan Berger <stefanb at linux.ibm.com>
> ---
> drivers/char/tpm/tpm-buf.c | 124 +++++----
> drivers/char/tpm/tpm-sysfs.c | 21 +-
> drivers/char/tpm/tpm.h | 1 -
> drivers/char/tpm/tpm1-cmd.c | 166 +++++------
> drivers/char/tpm/tpm2-cmd.c | 320 ++++++++++------------
> drivers/char/tpm/tpm2-sessions.c | 142 +++++-----
> drivers/char/tpm/tpm2-space.c | 44 ++-
> drivers/char/tpm/tpm_vtpm_proxy.c | 30 +-
> include/linux/tpm.h | 20 +-
> security/keys/trusted-keys/trusted_tpm1.c | 36 +--
> security/keys/trusted-keys/trusted_tpm2.c | 170 ++++++------
> 11 files changed, 508 insertions(+), 566 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index 1b9dee0d0681..73be8a87b472 100644
> --- a/drivers/char/tpm/tpm-buf.c
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -7,82 +7,109 @@
> #include <linux/module.h>
> #include <linux/tpm.h>
>
> -/**
> - * tpm_buf_init() - Allocate and initialize a TPM command
> - * @buf: A &tpm_buf
> - * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS
> - * @ordinal: A command ordinal
> - *
> - * Return: 0 or -ENOMEM
> - */
> -int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
> +static void __tpm_buf_size_invariant(struct tpm_buf *buf, u16 buf_size)
> {
> - buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> - if (!buf->data)
> - return -ENOMEM;
> -
> - tpm_buf_reset(buf, tag, ordinal);
> - return 0;
> + u32 buf_size_2 = (u32)buf->capacity + (u32)sizeof(*buf);
> +
> + if (!buf->capacity) {
> + if (buf_size > TPM_BUFSIZE) {
> + WARN(1, "%s: size overflow: %u\n", __func__, buf_size);
> + buf->flags |= TPM_BUF_INVALID;
> + }
> + } else {
> + if (buf_size != buf_size_2) {
> + WARN(1, "%s: size mismatch: %u != %u\n", __func__, buf_size,
> + buf_size_2);
> + buf->flags |= TPM_BUF_INVALID;
> + }
> + }
> }
> -EXPORT_SYMBOL_GPL(tpm_buf_init);
>
> -/**
> - * tpm_buf_reset() - Initialize a TPM command
> - * @buf: A &tpm_buf
> - * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS
> - * @ordinal: A command ordinal
> - */
> -void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
> +static void __tpm_buf_reset(struct tpm_buf *buf, u16 buf_size, u16 tag, u32 ordinal)
> {
> struct tpm_header *head = (struct tpm_header *)buf->data;
>
> + __tpm_buf_size_invariant(buf, buf_size);
> +
> + if (buf->flags & TPM_BUF_INVALID)
> + return;
> +
> WARN_ON(tag != TPM_TAG_RQU_COMMAND && tag != TPM2_ST_NO_SESSIONS &&
> tag != TPM2_ST_SESSIONS && tag != 0);
>
> buf->flags = 0;
> buf->length = sizeof(*head);
> + buf->capacity = buf_size - sizeof(*buf);
> + buf->handles = 0;
> head->tag = cpu_to_be16(tag);
> head->length = cpu_to_be32(sizeof(*head));
> head->ordinal = cpu_to_be32(ordinal);
> +}
> +
> +static void __tpm_buf_reset_sized(struct tpm_buf *buf, u16 buf_size)
> +{
> + __tpm_buf_size_invariant(buf, buf_size);
> +
> + if (buf->flags & TPM_BUF_INVALID)
> + return;
> +
> + buf->flags = TPM_BUF_TPM2B;
> + buf->length = 2;
> + buf->capacity = buf_size - sizeof(*buf);
> buf->handles = 0;
> + buf->data[0] = 0;
> + buf->data[1] = 0;
> }
> -EXPORT_SYMBOL_GPL(tpm_buf_reset);
>
> /**
> - * tpm_buf_init_sized() - Allocate and initialize a sized (TPM2B) buffer
> - * @buf: A @tpm_buf
> - *
> - * Return: 0 or -ENOMEM
> + * tpm_buf_init() - Initialize a TPM command
> + * @buf: A &tpm_buf
> + * @buf_size: Size of the buffer.
> */
> -int tpm_buf_init_sized(struct tpm_buf *buf)
> +void tpm_buf_init(struct tpm_buf *buf, u16 buf_size)
> {
> - buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> - if (!buf->data)
> - return -ENOMEM;
> + memset(buf, 0, buf_size);
> + __tpm_buf_reset(buf, buf_size, TPM_TAG_RQU_COMMAND, 0);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_init);
>
> - tpm_buf_reset_sized(buf);
> - return 0;
> +/**
> + * tpm_buf_init_sized() - Initialize a sized buffer
> + * @buf: A &tpm_buf
> + * @buf_size: Size of the buffer.
> + */
> +void tpm_buf_init_sized(struct tpm_buf *buf, u16 buf_size)
> +{
> + memset(buf, 0, buf_size);
> + __tpm_buf_reset_sized(buf, buf_size);
> }
> EXPORT_SYMBOL_GPL(tpm_buf_init_sized);
>
> /**
> - * tpm_buf_reset_sized() - Initialize a sized buffer
> + * tpm_buf_reset() - Re-initialize a TPM command
> * @buf: A &tpm_buf
> + * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS
> + * @ordinal: A command ordinal
> */
> -void tpm_buf_reset_sized(struct tpm_buf *buf)
> +void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
> {
> - buf->flags = TPM_BUF_TPM2B;
> - buf->length = 2;
> - buf->data[0] = 0;
> - buf->data[1] = 0;
> + u16 buf_size = buf->capacity + sizeof(*buf);
> +
> + __tpm_buf_reset(buf, buf_size, tag, ordinal);
> }
> -EXPORT_SYMBOL_GPL(tpm_buf_reset_sized);
> +EXPORT_SYMBOL_GPL(tpm_buf_reset);
>
> -void tpm_buf_destroy(struct tpm_buf *buf)
> +/**
> + * tpm_buf_reset_sized() - Re-initialize a sized buffer
> + * @buf: A &tpm_buf
> + */
> +void tpm_buf_reset_sized(struct tpm_buf *buf)
> {
> - free_page((unsigned long)buf->data);
> + u16 buf_size = buf->capacity + sizeof(*buf);
> +
> + __tpm_buf_reset_sized(buf, buf_size);
> }
> -EXPORT_SYMBOL_GPL(tpm_buf_destroy);
> +EXPORT_SYMBOL_GPL(tpm_buf_reset_sized);
>
> /**
> * tpm_buf_length() - Return the number of bytes consumed by the data
> @@ -90,8 +117,11 @@ EXPORT_SYMBOL_GPL(tpm_buf_destroy);
> *
> * Return: The number of bytes consumed by the buffer
> */
> -u32 tpm_buf_length(struct tpm_buf *buf)
> +u16 tpm_buf_length(struct tpm_buf *buf)
> {
> + if (buf->flags & TPM_BUF_INVALID)
> + return 0;
> +
> return buf->length;
> }
> EXPORT_SYMBOL_GPL(tpm_buf_length);
> @@ -104,10 +134,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_length);
> */
> void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length)
> {
> + u32 total_length = (u32)buf->length + (u32)new_length;
> +
> if (buf->flags & TPM_BUF_INVALID)
> return;
>
> - if ((buf->length + new_length) > PAGE_SIZE) {
> + if (total_length > (u32)buf->capacity) {
> WARN(1, "tpm_buf: write overflow\n");
> buf->flags |= TPM_BUF_INVALID;
> return;
> diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> index 94231f052ea7..f5dcadb1ab3c 100644
> --- a/drivers/char/tpm/tpm-sysfs.c
> +++ b/drivers/char/tpm/tpm-sysfs.c
> @@ -32,28 +32,29 @@ struct tpm_readpubek_out {
> static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
> char *buf)
> {
> - struct tpm_buf tpm_buf;
> struct tpm_readpubek_out *out;
> int i;
> char *str = buf;
> struct tpm_chip *chip = to_tpm_chip(dev);
> char anti_replay[20];
>
> + struct tpm_buf *tpm_buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!tpm_buf)
> + return -ENOMEM;
> +
> memset(&anti_replay, 0, sizeof(anti_replay));
>
> if (tpm_try_get_ops(chip))
> return 0;
>
> - if (tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK))
> - goto out_ops;
> -
> - tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
> + tpm_buf_init(tpm_buf, TPM_BUFSIZE);
> + tpm_buf_reset(tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK);
> + tpm_buf_append(tpm_buf, anti_replay, sizeof(anti_replay));
>
> - if (tpm_transmit_cmd(chip, &tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE,
> - "attempting to read the PUBEK"))
> - goto out_buf;
> + if (tpm_transmit_cmd(chip, tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE, "TPM_ReadPubek"))
> + goto out_ops;
>
> - out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
> + out = (struct tpm_readpubek_out *)&tpm_buf->data[10];
> str +=
> sprintf(str,
> "Algorithm: %4ph\n"
> @@ -71,8 +72,6 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
> for (i = 0; i < 256; i += 16)
> str += sprintf(str, "%16ph\n", &out->modulus[i]);
>
> -out_buf:
> - tpm_buf_destroy(&tpm_buf);
> out_ops:
> tpm_put_ops(chip);
> return str - buf;
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 02c07fef41ba..5395927c62fc 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -32,7 +32,6 @@
> #endif
>
> #define TPM_MINOR 224 /* officially assigned */
> -#define TPM_BUFSIZE 4096
> #define TPM_NUM_DEVICES 65536
> #define TPM_RETRY 50
>
> diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
> index b49a790f1bd5..11090053ef54 100644
> --- a/drivers/char/tpm/tpm1-cmd.c
> +++ b/drivers/char/tpm/tpm1-cmd.c
> @@ -323,20 +323,14 @@ unsigned long tpm1_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
> */
> static int tpm1_startup(struct tpm_chip *chip)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - dev_info(&chip->dev, "starting up the TPM manually\n");
> -
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
> - if (rc < 0)
> - return rc;
> -
> - tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
> -
> - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
> - tpm_buf_destroy(&buf);
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
> + tpm_buf_append_u16(buf, TPM_ST_CLEAR);
> + return tpm_transmit_cmd(chip, buf, 0, "TPM_Startup");
> }
>
> int tpm1_get_timeouts(struct tpm_chip *chip)
> @@ -463,50 +457,47 @@ int tpm1_get_timeouts(struct tpm_chip *chip)
> int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
> const char *log_msg)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
> - if (rc)
> - return rc;
> -
> - tpm_buf_append_u32(&buf, pcr_idx);
> - tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
> -
> - rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, log_msg);
> - tpm_buf_destroy(&buf);
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
> + tpm_buf_append_u32(buf, pcr_idx);
> + tpm_buf_append(buf, hash, TPM_DIGEST_SIZE);
> + return tpm_transmit_cmd(chip, buf, TPM_DIGEST_SIZE, log_msg);
> }
>
> #define TPM_ORD_GET_CAP 101
> ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> const char *desc, size_t min_cap_length)
> {
> - struct tpm_buf buf;
> int rc;
>
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
>
> if (subcap_id == TPM_CAP_VERSION_1_1 ||
> subcap_id == TPM_CAP_VERSION_1_2) {
> - tpm_buf_append_u32(&buf, subcap_id);
> - tpm_buf_append_u32(&buf, 0);
> + tpm_buf_append_u32(buf, subcap_id);
> + tpm_buf_append_u32(buf, 0);
> } else {
> if (subcap_id == TPM_CAP_FLAG_PERM ||
> subcap_id == TPM_CAP_FLAG_VOL)
> - tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
> + tpm_buf_append_u32(buf, TPM_CAP_FLAG);
> else
> - tpm_buf_append_u32(&buf, TPM_CAP_PROP);
> + tpm_buf_append_u32(buf, TPM_CAP_PROP);
>
> - tpm_buf_append_u32(&buf, 4);
> - tpm_buf_append_u32(&buf, subcap_id);
> + tpm_buf_append_u32(buf, 4);
> + tpm_buf_append_u32(buf, subcap_id);
> }
> - rc = tpm_transmit_cmd(chip, &buf, min_cap_length, desc);
> + rc = tpm_transmit_cmd(chip, buf, min_cap_length, desc);
> if (!rc)
> - *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
> - tpm_buf_destroy(&buf);
> + *cap = *(cap_t *)&buf->data[TPM_HEADER_SIZE + 4];
> return rc;
> }
> EXPORT_SYMBOL_GPL(tpm1_getcap);
> @@ -531,81 +522,69 @@ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> {
> struct tpm1_get_random_out *out;
> u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
> - struct tpm_buf buf;
> u32 total = 0;
> int retries = 5;
> u32 recd;
> int rc;
>
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> + tpm_buf_init(buf, TPM_BUFSIZE);
> do {
> - tpm_buf_append_u32(&buf, num_bytes);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
> + tpm_buf_append_u32(buf, num_bytes);
>
> - rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
> - "attempting get random");
> + rc = tpm_transmit_cmd(chip, buf, sizeof(out->rng_data_len), "TPM_GetRandom");
> if (rc) {
> if (rc > 0)
> rc = -EIO;
> - goto out;
> + return rc;
> }
>
> - out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
> + out = (struct tpm1_get_random_out *)&buf->data[TPM_HEADER_SIZE];
>
> recd = be32_to_cpu(out->rng_data_len);
> - if (recd > num_bytes) {
> - rc = -EFAULT;
> - goto out;
> - }
> + if (recd > num_bytes)
> + return -EFAULT;
> +
> + if (buf->length < TPM_HEADER_SIZE +
> + sizeof(out->rng_data_len) + recd)
> + return -EFAULT;
>
> - if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
> - sizeof(out->rng_data_len) + recd) {
> - rc = -EFAULT;
> - goto out;
> - }
> memcpy(dest, out->rng_data, recd);
>
> dest += recd;
> total += recd;
> num_bytes -= recd;
> -
> - tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
> } while (retries-- && total < max);
>
> rc = total ? (int)total : -EIO;
> -out:
> - tpm_buf_destroy(&buf);
> return rc;
> }
>
> #define TPM_ORD_PCRREAD 21
> int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> {
> - struct tpm_buf buf;
> int rc;
>
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> - tpm_buf_append_u32(&buf, pcr_idx);
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);
> + tpm_buf_append_u32(buf, pcr_idx);
>
> - rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE,
> - "attempting to read a pcr value");
> + rc = tpm_transmit_cmd(chip, buf, TPM_DIGEST_SIZE, "TPM_PCRRead");
> if (rc)
> - goto out;
> -
> - if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) {
> - rc = -EFAULT;
> - goto out;
> - }
> + return rc;
>
> - memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);
> + if (buf->length < TPM_DIGEST_SIZE)
> + return -EFAULT;
>
> -out:
> - tpm_buf_destroy(&buf);
> + memcpy(res_buf, &buf->data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);
> return rc;
> }
>
> @@ -619,16 +598,13 @@ int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> */
> static int tpm1_continue_selftest(struct tpm_chip *chip)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_CONTINUE_SELFTEST);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> - rc = tpm_transmit_cmd(chip, &buf, 0, "continue selftest");
> - tpm_buf_destroy(&buf);
> - return rc;
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_CONTINUE_SELFTEST);
> + return tpm_transmit_cmd(chip, buf, 0, "TPM_ContinueSelfTest");
> }
>
> /**
> @@ -742,22 +718,24 @@ int tpm1_auto_startup(struct tpm_chip *chip)
> int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
> {
> u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
> - struct tpm_buf buf;
> unsigned int try;
> int rc;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> /* for buggy tpm, flush pcrs with extend to selected dummy */
> if (tpm_suspend_pcr)
> rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
> "extending dummy pcr before suspend");
>
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
> - if (rc)
> - return rc;
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
> +
> /* now do the actual savestate */
> for (try = 0; try < TPM_RETRY; try++) {
> - rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
> + rc = tpm_transmit_cmd(chip, buf, 0, NULL);
> /*
> * If the TPM indicates that it is too busy to respond to
> * this command then retry before giving up. It can take
> @@ -772,7 +750,7 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
> break;
> tpm_msleep(TPM_TIMEOUT_RETRY);
>
> - tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
> }
>
> if (rc)
> @@ -782,8 +760,6 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
> dev_warn(&chip->dev, "TPM savestate took %dms\n",
> try * TPM_TIMEOUT_RETRY);
>
> - tpm_buf_destroy(&buf);
> -
> return rc;
> }
>
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 82076b6cfcf7..2682f5ec09cb 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -119,12 +119,15 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
> {
> int i;
> int rc;
> - struct tpm_buf buf;
> struct tpm2_pcr_read_out *out;
> u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
> u16 digest_size;
> u16 expected_digest_size = 0;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> if (pcr_idx >= TPM2_PLATFORM_PCR)
> return -EINVAL;
>
> @@ -139,36 +142,31 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
> expected_digest_size = chip->allocated_banks[i].digest_size;
> }
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
> - if (rc)
> - return rc;
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
>
> pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
>
> - tpm_buf_append_u32(&buf, 1);
> - tpm_buf_append_u16(&buf, digest->alg_id);
> - tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
> - tpm_buf_append(&buf, (const unsigned char *)pcr_select,
> + tpm_buf_append_u32(buf, 1);
> + tpm_buf_append_u16(buf, digest->alg_id);
> + tpm_buf_append_u8(buf, TPM2_PCR_SELECT_MIN);
> + tpm_buf_append(buf, (const unsigned char *)pcr_select,
> sizeof(pcr_select));
>
> - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
> + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_PCR_Read");
> if (rc)
> - goto out;
> + return rc;
>
> - out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
> + out = (struct tpm2_pcr_read_out *)&buf->data[TPM_HEADER_SIZE];
> digest_size = be16_to_cpu(out->digest_size);
> if (digest_size > sizeof(digest->digest) ||
> - (!digest_size_ptr && digest_size != expected_digest_size)) {
> - rc = -EINVAL;
> - goto out;
> - }
> + (!digest_size_ptr && digest_size != expected_digest_size))
> + return rc;
>
> if (digest_size_ptr)
> *digest_size_ptr = digest_size;
>
> memcpy(digest->digest, out->digest, digest_size);
> -out:
> - tpm_buf_destroy(&buf);
> return rc;
> }
>
> @@ -184,56 +182,52 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
> int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> struct tpm_digest *digests)
> {
> - struct tpm_buf buf;
> int rc;
> int i;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> if (!disable_pcr_integrity) {
> rc = tpm2_start_auth_session(chip);
> if (rc)
> return rc;
> }
>
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
> - if (rc) {
> - if (!disable_pcr_integrity)
> - tpm2_end_auth_session(chip);
> - return rc;
> - }
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
>
> if (!disable_pcr_integrity) {
> - rc = tpm_buf_append_name(chip, &buf, pcr_idx, NULL);
> - if (rc) {
> - tpm_buf_destroy(&buf);
> + rc = tpm_buf_append_name(chip, buf, pcr_idx, NULL);
> + if (rc)
> return rc;
> - }
> - tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
> + tpm_buf_append_hmac_session(chip, buf, 0, NULL, 0);
> } else {
> - tpm_buf_append_handle(&buf, pcr_idx);
> - tpm_buf_append_auth(chip, &buf, NULL, 0);
> + tpm_buf_append_handle(buf, pcr_idx);
> + tpm_buf_append_auth(chip, buf, NULL, 0);
> }
>
> - tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
> + tpm_buf_append_u32(buf, chip->nr_allocated_banks);
>
> for (i = 0; i < chip->nr_allocated_banks; i++) {
> - tpm_buf_append_u16(&buf, digests[i].alg_id);
> - tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
> + tpm_buf_append_u16(buf, digests[i].alg_id);
> + tpm_buf_append(buf, (const unsigned char *)&digests[i].digest,
> chip->allocated_banks[i].digest_size);
> }
> + if (buf->flags & TPM_BUF_INVALID)
> + return -EINVAL;
>
> if (!disable_pcr_integrity) {
> - rc = tpm_buf_fill_hmac_session(chip, &buf);
> - if (rc) {
> - tpm_buf_destroy(&buf);
> + rc = tpm_buf_fill_hmac_session(chip, buf);
> + if (rc)
> return rc;
> - }
> }
>
> - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
> - if (!disable_pcr_integrity)
> - rc = tpm_buf_check_hmac_response(chip, &buf, rc);
> + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_PCR_Extend");
>
> - tpm_buf_destroy(&buf);
> + if (!disable_pcr_integrity)
> + rc = tpm_buf_check_hmac_response(chip, buf, rc);
>
> return rc;
> }
> @@ -258,7 +252,6 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> {
> struct tpm2_get_random_out *out;
> struct tpm_header *head;
> - struct tpm_buf buf;
> u32 recd;
> u32 num_bytes = max;
> int err;
> @@ -270,61 +263,58 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> if (!num_bytes || max > TPM_MAX_RNG_DATA)
> return -EINVAL;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> err = tpm2_start_auth_session(chip);
> if (err)
> return err;
>
> - err = tpm_buf_init(&buf, 0, 0);
> - if (err) {
> - tpm2_end_auth_session(chip);
> - return err;
> - }
> -
> + tpm_buf_init(buf, TPM_BUFSIZE);
> do {
> - tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
> if (tpm2_chip_auth(chip)) {
> - tpm_buf_append_hmac_session(chip, &buf,
> + tpm_buf_append_hmac_session(chip, buf,
> TPM2_SA_ENCRYPT |
> TPM2_SA_CONTINUE_SESSION,
> NULL, 0);
> } else {
> - offset = buf.handles * 4 + TPM_HEADER_SIZE;
> - head = (struct tpm_header *)buf.data;
> - if (tpm_buf_length(&buf) == offset)
> + offset = buf->handles * 4 + TPM_HEADER_SIZE;
> + head = (struct tpm_header *)buf->data;
> + if (tpm_buf_length(buf) == offset)
> head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
> }
> - tpm_buf_append_u16(&buf, num_bytes);
> - err = tpm_buf_fill_hmac_session(chip, &buf);
> - if (err) {
> - tpm_buf_destroy(&buf);
> + tpm_buf_append_u16(buf, num_bytes);
> +
> + err = tpm_buf_fill_hmac_session(chip, buf);
> + if (err)
> return err;
> - }
>
> - err = tpm_transmit_cmd(chip, &buf,
> + err = tpm_transmit_cmd(chip, buf,
> offsetof(struct tpm2_get_random_out,
> buffer),
> - "attempting get random");
> - err = tpm_buf_check_hmac_response(chip, &buf, err);
> + "TPM2_GetRandom");
> + err = tpm_buf_check_hmac_response(chip, buf, err);
> if (err) {
> if (err > 0)
> err = -EIO;
> - goto out;
> + return err;
> }
>
> - head = (struct tpm_header *)buf.data;
> + head = (struct tpm_header *)buf->data;
> offset = TPM_HEADER_SIZE;
> /* Skip the parameter size field: */
> if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
> offset += 4;
>
> - out = (struct tpm2_get_random_out *)&buf.data[offset];
> + out = (struct tpm2_get_random_out *)&buf->data[offset];
> recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
> - if (tpm_buf_length(&buf) <
> + if (tpm_buf_length(buf) <
> TPM_HEADER_SIZE +
> offsetof(struct tpm2_get_random_out, buffer) +
> recd) {
> - err = -EFAULT;
> - goto out;
> + return -EFAULT;
> }
> memcpy(dest_ptr, out->buffer, recd);
>
> @@ -333,13 +323,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> num_bytes -= recd;
> } while (retries-- && total < max);
>
> - tpm_buf_destroy(&buf);
> -
> return total ? total : -EIO;
> -out:
> - tpm_buf_destroy(&buf);
> - tpm2_end_auth_session(chip);
> - return err;
> }
>
> /**
> @@ -349,20 +333,18 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> */
> void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
> - if (rc) {
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf) {
> dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
> handle);
> return;
> }
>
> - tpm_buf_append_u32(&buf, handle);
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
> + tpm_buf_append_u32(buf, handle);
>
> - tpm_transmit_cmd(chip, &buf, 0, "flushing context");
> - tpm_buf_destroy(&buf);
> + tpm_transmit_cmd(chip, buf, 0, "TPM2_FlushContext");
> }
> EXPORT_SYMBOL_GPL(tpm2_flush_context);
>
> @@ -389,19 +371,20 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
> const char *desc)
> {
> struct tpm2_get_cap_out *out;
> - struct tpm_buf buf;
> int rc;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> - if (rc)
> - return rc;
> - tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
> - tpm_buf_append_u32(&buf, property_id);
> - tpm_buf_append_u32(&buf, 1);
> - rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> + tpm_buf_append_u32(buf, TPM2_CAP_TPM_PROPERTIES);
> + tpm_buf_append_u32(buf, property_id);
> + tpm_buf_append_u32(buf, 1);
> + rc = tpm_transmit_cmd(chip, buf, 0, NULL);
> if (!rc) {
> - out = (struct tpm2_get_cap_out *)
> - &buf.data[TPM_HEADER_SIZE];
> + out = (struct tpm2_get_cap_out *)&buf->data[TPM_HEADER_SIZE];
> /*
> * To prevent failing boot up of some systems, Infineon TPM2.0
> * returns SUCCESS on TPM2_Startup in field upgrade mode. Also
> @@ -413,7 +396,6 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
> else
> rc = -ENODATA;
> }
> - tpm_buf_destroy(&buf);
> return rc;
> }
> EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
> @@ -430,15 +412,14 @@ EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
> */
> void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
> - if (rc)
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> return;
> - tpm_buf_append_u16(&buf, shutdown_type);
> - tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
> - tpm_buf_destroy(&buf);
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
> + tpm_buf_append_u16(buf, shutdown_type);
> + tpm_transmit_cmd(chip, buf, 0, "TPM2_Shutdown");
> }
>
> /**
> @@ -456,20 +437,19 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
> */
> static int tpm2_do_selftest(struct tpm_chip *chip)
> {
> - struct tpm_buf buf;
> int full;
> int rc;
>
> - for (full = 0; full < 2; full++) {
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
> - if (rc)
> - return rc;
> -
> - tpm_buf_append_u8(&buf, full);
> - rc = tpm_transmit_cmd(chip, &buf, 0,
> - "attempting the self test");
> - tpm_buf_destroy(&buf);
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
> + for (full = 0; full < 2; full++) {
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
> + tpm_buf_append_u8(buf, full);
> + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_SelfTest");
> if (rc == TPM2_RC_TESTING)
> rc = TPM2_RC_SUCCESS;
> if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
> @@ -494,23 +474,24 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
> int tpm2_probe(struct tpm_chip *chip)
> {
> struct tpm_header *out;
> - struct tpm_buf buf;
> int rc;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> - if (rc)
> - return rc;
> - tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
> - tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
> - tpm_buf_append_u32(&buf, 1);
> - rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> + tpm_buf_append_u32(buf, TPM2_CAP_TPM_PROPERTIES);
> + tpm_buf_append_u32(buf, TPM_PT_TOTAL_COMMANDS);
> + tpm_buf_append_u32(buf, 1);
> + rc = tpm_transmit_cmd(chip, buf, 0, NULL);
> /* We ignore TPM return codes on purpose. */
> if (rc >= 0) {
> - out = (struct tpm_header *)buf.data;
> + out = (struct tpm_header *)buf->data;
> if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
> chip->flags |= TPM_CHIP_FLAG_TPM2;
> }
> - tpm_buf_destroy(&buf);
> return 0;
> }
> EXPORT_SYMBOL_GPL(tpm2_probe);
> @@ -550,7 +531,6 @@ struct tpm2_pcr_selection {
> ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> {
> struct tpm2_pcr_selection pcr_selection;
> - struct tpm_buf buf;
> void *marker;
> void *end;
> void *pcr_select_offset;
> @@ -562,39 +542,37 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> int rc;
> int i = 0;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> - tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
> - tpm_buf_append_u32(&buf, 0);
> - tpm_buf_append_u32(&buf, 1);
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> + tpm_buf_append_u32(buf, TPM2_CAP_PCRS);
> + tpm_buf_append_u32(buf, 0);
> + tpm_buf_append_u32(buf, 1);
>
> - rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
> + rc = tpm_transmit_cmd(chip, buf, 9, "TPM2_GetCapability(PCRS)");
> if (rc)
> - goto out;
> + return rc;
>
> - nr_possible_banks = be32_to_cpup(
> - (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
> + nr_possible_banks = be32_to_cpup((__be32 *)&buf->data[TPM_HEADER_SIZE + 5]);
> if (nr_possible_banks > TPM2_MAX_PCR_BANKS) {
> pr_err("tpm: out of bank capacity: %u > %u\n",
> nr_possible_banks, TPM2_MAX_PCR_BANKS);
> - rc = -ENOMEM;
> - goto out;
> + return -ENOMEM;
> }
>
> - marker = &buf.data[TPM_HEADER_SIZE + 9];
> + marker = &buf->data[TPM_HEADER_SIZE + 9];
>
> - rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
> - end = &buf.data[rsp_len];
> + rsp_len = be32_to_cpup((__be32 *)&buf->data[2]);
> + end = &buf->data[rsp_len];
>
> for (i = 0; i < nr_possible_banks; i++) {
> pcr_select_offset = marker +
> offsetof(struct tpm2_pcr_selection, size_of_select);
> - if (pcr_select_offset >= end) {
> - rc = -EFAULT;
> - break;
> - }
> + if (pcr_select_offset >= end)
> + return -EFAULT;
>
> memcpy(&pcr_selection, marker, sizeof(pcr_selection));
> hash_alg = be16_to_cpu(pcr_selection.hash_alg);
> @@ -606,7 +584,7 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
>
> rc = tpm2_init_bank_info(chip, nr_alloc_banks);
> if (rc < 0)
> - break;
> + return rc;
>
> nr_alloc_banks++;
> }
> @@ -618,21 +596,21 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> }
>
> chip->nr_allocated_banks = nr_alloc_banks;
> -out:
> - tpm_buf_destroy(&buf);
> -
> - return rc;
> + return 0;
> }
>
> int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
> {
> - struct tpm_buf buf;
> u32 nr_commands;
> __be32 *attrs;
> u32 cc;
> int i;
> int rc;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
> if (rc)
> goto out;
> @@ -649,30 +627,24 @@ int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
> goto out;
> }
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> - if (rc)
> - goto out;
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> + tpm_buf_append_u32(buf, TPM2_CAP_COMMANDS);
> + tpm_buf_append_u32(buf, TPM2_CC_FIRST);
> + tpm_buf_append_u32(buf, nr_commands);
>
> - tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
> - tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
> - tpm_buf_append_u32(&buf, nr_commands);
> -
> - rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
> - if (rc) {
> - tpm_buf_destroy(&buf);
> + rc = tpm_transmit_cmd(chip, buf, 9 + 4 * nr_commands, NULL);
> + if (rc)
> goto out;
> - }
>
> - if (nr_commands !=
> - be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
> + if (nr_commands != be32_to_cpup((__be32 *)&buf->data[TPM_HEADER_SIZE + 5])) {
> rc = -EFAULT;
> - tpm_buf_destroy(&buf);
> goto out;
> }
>
> chip->nr_commands = nr_commands;
>
> - attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
> + attrs = (__be32 *)&buf->data[TPM_HEADER_SIZE + 9];
> for (i = 0; i < nr_commands; i++, attrs++) {
> chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
> cc = chip->cc_attrs_tbl[i] & 0xFFFF;
> @@ -684,8 +656,6 @@ int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
> }
> }
>
> - tpm_buf_destroy(&buf);
> -
> out:
> if (rc > 0)
> rc = -ENODEV;
> @@ -706,20 +676,14 @@ EXPORT_SYMBOL_GPL(tpm2_get_cc_attrs_tbl);
>
> static int tpm2_startup(struct tpm_chip *chip)
> {
> - struct tpm_buf buf;
> - int rc;
> -
> - dev_info(&chip->dev, "starting up the TPM manually\n");
> -
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
> - if (rc < 0)
> - return rc;
> -
> - tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
> - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
> - tpm_buf_destroy(&buf);
> -
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
> + tpm_buf_append_u16(buf, TPM2_SU_CLEAR);
> + return tpm_transmit_cmd(chip, buf, 0, "TPM2_Startup");
> }
>
> /**
> diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
> index 92d116d73c6f..79f27a46bd7f 100644
> --- a/drivers/char/tpm/tpm2-sessions.c
> +++ b/drivers/char/tpm/tpm2-sessions.c
> @@ -168,7 +168,6 @@ static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name)
> u32 mso = tpm2_handle_mso(handle);
> off_t offset = TPM_HEADER_SIZE;
> int rc, name_size_alg;
> - struct tpm_buf buf;
>
> if (mso != TPM2_MSO_PERSISTENT && mso != TPM2_MSO_VOLATILE &&
> mso != TPM2_MSO_NVRAM) {
> @@ -176,47 +175,41 @@ static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name)
> return sizeof(u32);
> }
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> - tpm_buf_append_u32(&buf, handle);
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC);
> + tpm_buf_append_u32(buf, handle);
>
> - rc = tpm_transmit_cmd(chip, &buf, 0, "TPM2_ReadPublic");
> - if (rc) {
> - tpm_buf_destroy(&buf);
> + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_ReadPublic");
> + if (rc)
> return tpm_ret_to_err(rc);
> - }
>
> /* Skip TPMT_PUBLIC: */
> - offset += tpm_buf_read_u16(&buf, &offset);
> + offset += tpm_buf_read_u16(buf, &offset);
>
> /*
> * Ensure space for the length field of TPM2B_NAME and hashAlg field of
> * TPMT_HA (the extra four bytes).
> */
> - if (offset + 4 > tpm_buf_length(&buf)) {
> - tpm_buf_destroy(&buf);
> + if (offset + 4 > tpm_buf_length(buf))
> return -EIO;
> - }
>
> - rc = tpm_buf_read_u16(&buf, &offset);
> - name_size_alg = name_size(&buf.data[offset]);
> + rc = tpm_buf_read_u16(buf, &offset);
> + name_size_alg = name_size(&buf->data[offset]);
>
> if (name_size_alg < 0)
> return name_size_alg;
>
> - if (rc != name_size_alg) {
> - tpm_buf_destroy(&buf);
> + if (rc != name_size_alg)
> return -EIO;
> - }
>
> - if (offset + rc > tpm_buf_length(&buf)) {
> - tpm_buf_destroy(&buf);
> + if (offset + rc > tpm_buf_length(buf))
> return -EIO;
> - }
>
> - memcpy(name, &buf.data[offset], rc);
> + memcpy(name, &buf->data[offset], rc);
> return name_size_alg;
> }
> #endif /* CONFIG_TCG_TPM2_HMAC */
> @@ -982,7 +975,6 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key)
> int tpm2_start_auth_session(struct tpm_chip *chip)
> {
> struct tpm2_auth *auth;
> - struct tpm_buf buf;
> u32 null_key;
> int rc;
>
> @@ -991,6 +983,10 @@ int tpm2_start_auth_session(struct tpm_chip *chip)
> return 0;
> }
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> auth = kzalloc(sizeof(*auth), GFP_KERNEL);
> if (!auth)
> return -ENOMEM;
> @@ -1001,41 +997,37 @@ int tpm2_start_auth_session(struct tpm_chip *chip)
>
> auth->session = TPM_HEADER_SIZE;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_START_AUTH_SESS);
> - if (rc)
> - goto out;
> -
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_START_AUTH_SESS);
> /* salt key handle */
> - tpm_buf_append_u32(&buf, null_key);
> + tpm_buf_append_u32(buf, null_key);
> /* bind key handle */
> - tpm_buf_append_u32(&buf, TPM2_RH_NULL);
> + tpm_buf_append_u32(buf, TPM2_RH_NULL);
> /* nonce caller */
> get_random_bytes(auth->our_nonce, sizeof(auth->our_nonce));
> - tpm_buf_append_u16(&buf, sizeof(auth->our_nonce));
> - tpm_buf_append(&buf, auth->our_nonce, sizeof(auth->our_nonce));
> + tpm_buf_append_u16(buf, sizeof(auth->our_nonce));
> + tpm_buf_append(buf, auth->our_nonce, sizeof(auth->our_nonce));
>
> /* append encrypted salt and squirrel away unencrypted in auth */
> - tpm_buf_append_salt(&buf, chip, auth);
> + tpm_buf_append_salt(buf, chip, auth);
> /* session type (HMAC, audit or policy) */
> - tpm_buf_append_u8(&buf, TPM2_SE_HMAC);
> + tpm_buf_append_u8(buf, TPM2_SE_HMAC);
>
> /* symmetric encryption parameters */
> /* symmetric algorithm */
> - tpm_buf_append_u16(&buf, TPM_ALG_AES);
> + tpm_buf_append_u16(buf, TPM_ALG_AES);
> /* bits for symmetric algorithm */
> - tpm_buf_append_u16(&buf, AES_KEY_BITS);
> + tpm_buf_append_u16(buf, AES_KEY_BITS);
> /* symmetric algorithm mode (must be CFB) */
> - tpm_buf_append_u16(&buf, TPM_ALG_CFB);
> + tpm_buf_append_u16(buf, TPM_ALG_CFB);
> /* hash algorithm for session */
> - tpm_buf_append_u16(&buf, TPM_ALG_SHA256);
> + tpm_buf_append_u16(buf, TPM_ALG_SHA256);
>
> - rc = tpm_ret_to_err(tpm_transmit_cmd(chip, &buf, 0, "StartAuthSession"));
> + rc = tpm_ret_to_err(tpm_transmit_cmd(chip, buf, 0, "TPM2_StartAuthSession"));
> tpm2_flush_context(chip, null_key);
>
> if (rc == TPM2_RC_SUCCESS)
> - rc = tpm2_parse_start_auth_session(auth, &buf);
> -
> - tpm_buf_destroy(&buf);
> + rc = tpm2_parse_start_auth_session(auth, buf);
>
> if (rc == TPM2_RC_SUCCESS) {
> chip->auth = auth;
> @@ -1257,18 +1249,18 @@ static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy,
> u32 *handle, u8 *name)
> {
> int rc;
> - struct tpm_buf buf;
> - struct tpm_buf template;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE_PRIMARY);
> - if (rc)
> - return rc;
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
>
> - rc = tpm_buf_init_sized(&template);
> - if (rc) {
> - tpm_buf_destroy(&buf);
> - return rc;
> - }
> + struct tpm_buf *template __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!template)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE_PRIMARY);
> + tpm_buf_init_sized(template, TPM_BUFSIZE);
>
> /*
> * create the template. Note: in order for userspace to
> @@ -1280,75 +1272,71 @@ static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy,
> */
>
> /* key type */
> - tpm_buf_append_u16(&template, TPM_ALG_ECC);
> + tpm_buf_append_u16(template, TPM_ALG_ECC);
>
> /* name algorithm */
> - tpm_buf_append_u16(&template, TPM_ALG_SHA256);
> + tpm_buf_append_u16(template, TPM_ALG_SHA256);
>
> /* object properties */
> - tpm_buf_append_u32(&template, TPM2_OA_NULL_KEY);
> + tpm_buf_append_u32(template, TPM2_OA_NULL_KEY);
>
> /* sauth policy (empty) */
> - tpm_buf_append_u16(&template, 0);
> + tpm_buf_append_u16(template, 0);
>
> /* BEGIN parameters: key specific; for ECC*/
>
> /* symmetric algorithm */
> - tpm_buf_append_u16(&template, TPM_ALG_AES);
> + tpm_buf_append_u16(template, TPM_ALG_AES);
>
> /* bits for symmetric algorithm */
> - tpm_buf_append_u16(&template, AES_KEY_BITS);
> + tpm_buf_append_u16(template, AES_KEY_BITS);
>
> /* algorithm mode (must be CFB) */
> - tpm_buf_append_u16(&template, TPM_ALG_CFB);
> + tpm_buf_append_u16(template, TPM_ALG_CFB);
>
> /* scheme (NULL means any scheme) */
> - tpm_buf_append_u16(&template, TPM_ALG_NULL);
> + tpm_buf_append_u16(template, TPM_ALG_NULL);
>
> /* ECC Curve ID */
> - tpm_buf_append_u16(&template, TPM2_ECC_NIST_P256);
> + tpm_buf_append_u16(template, TPM2_ECC_NIST_P256);
>
> /* KDF Scheme */
> - tpm_buf_append_u16(&template, TPM_ALG_NULL);
> + tpm_buf_append_u16(template, TPM_ALG_NULL);
>
> /* unique: key specific; for ECC it is two zero size points */
> - tpm_buf_append_u16(&template, 0);
> - tpm_buf_append_u16(&template, 0);
> + tpm_buf_append_u16(template, 0);
> + tpm_buf_append_u16(template, 0);
>
> /* END parameters */
>
> /* primary handle */
> - tpm_buf_append_u32(&buf, hierarchy);
> - tpm_buf_append_empty_auth(&buf, TPM2_RS_PW);
> + tpm_buf_append_u32(buf, hierarchy);
> + tpm_buf_append_empty_auth(buf, TPM2_RS_PW);
>
> /* sensitive create size is 4 for two empty buffers */
> - tpm_buf_append_u16(&buf, 4);
> + tpm_buf_append_u16(buf, 4);
>
> /* sensitive create auth data (empty) */
> - tpm_buf_append_u16(&buf, 0);
> + tpm_buf_append_u16(buf, 0);
>
> /* sensitive create sensitive data (empty) */
> - tpm_buf_append_u16(&buf, 0);
> + tpm_buf_append_u16(buf, 0);
>
> /* the public template */
> - tpm_buf_append(&buf, template.data, template.length);
> - tpm_buf_destroy(&template);
> + tpm_buf_append(buf, template->data, template->length);
>
> /* outside info (empty) */
> - tpm_buf_append_u16(&buf, 0);
> + tpm_buf_append_u16(buf, 0);
>
> /* creation PCR (none) */
> - tpm_buf_append_u32(&buf, 0);
> + tpm_buf_append_u32(buf, 0);
>
> - rc = tpm_transmit_cmd(chip, &buf, 0,
> - "attempting to create NULL primary");
> + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_CreatePrimary");
>
> if (rc == TPM2_RC_SUCCESS)
> - rc = tpm2_parse_create_primary(chip, &buf, handle, hierarchy,
> + rc = tpm2_parse_create_primary(chip, buf, handle, hierarchy,
> name);
>
> - tpm_buf_destroy(&buf);
> -
> return rc;
> }
>
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index 60354cd53b5c..cbf86ff5931f 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -71,24 +71,25 @@ void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
> int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> unsigned int *offset, u32 *handle)
> {
> - struct tpm_buf tbuf;
> struct tpm2_context *ctx;
> unsigned int body_size;
> int rc;
>
> - rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
> - if (rc)
> - return rc;
> + struct tpm_buf *tbuf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!tbuf)
> + return -ENOMEM;
> +
> + tpm_buf_init(tbuf, TPM_BUFSIZE);
> + tpm_buf_reset(tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
>
> ctx = (struct tpm2_context *)&buf[*offset];
> body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
> - tpm_buf_append(&tbuf, &buf[*offset], body_size);
> + tpm_buf_append(tbuf, &buf[*offset], body_size);
>
> - rc = tpm_transmit_cmd(chip, &tbuf, 4, NULL);
> + rc = tpm_transmit_cmd(chip, tbuf, 4, NULL);
> if (rc < 0) {
> dev_warn(&chip->dev, "%s: failed with a system error %d\n",
> __func__, rc);
> - tpm_buf_destroy(&tbuf);
> return -EFAULT;
> } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE ||
> rc == TPM2_RC_REFERENCE_H0) {
> @@ -103,64 +104,55 @@ int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> * flushed outside the space
> */
> *handle = 0;
> - tpm_buf_destroy(&tbuf);
> return -ENOENT;
> } else if (tpm2_rc_value(rc) == TPM2_RC_INTEGRITY) {
> - tpm_buf_destroy(&tbuf);
> return -EINVAL;
> } else if (rc > 0) {
> dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
> __func__, rc);
> - tpm_buf_destroy(&tbuf);
> return -EFAULT;
> }
>
> - *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]);
> + *handle = be32_to_cpup((__be32 *)&tbuf->data[TPM_HEADER_SIZE]);
> *offset += body_size;
> -
> - tpm_buf_destroy(&tbuf);
> return 0;
> }
>
> int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
> unsigned int buf_size, unsigned int *offset)
> {
> - struct tpm_buf tbuf;
> unsigned int body_size;
> int rc;
>
> - rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE);
> - if (rc)
> - return rc;
> + struct tpm_buf *tbuf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!tbuf)
> + return -ENOMEM;
>
> - tpm_buf_append_u32(&tbuf, handle);
> + tpm_buf_init(tbuf, TPM_BUFSIZE);
> + tpm_buf_reset(tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE);
> + tpm_buf_append_u32(tbuf, handle);
>
> - rc = tpm_transmit_cmd(chip, &tbuf, 0, NULL);
> + rc = tpm_transmit_cmd(chip, tbuf, 0, NULL);
> if (rc < 0) {
> dev_warn(&chip->dev, "%s: failed with a system error %d\n",
> __func__, rc);
> - tpm_buf_destroy(&tbuf);
> return -EFAULT;
> } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) {
> - tpm_buf_destroy(&tbuf);
> return -ENOENT;
> } else if (rc) {
> dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
> __func__, rc);
> - tpm_buf_destroy(&tbuf);
> return -EFAULT;
> }
>
> - body_size = tpm_buf_length(&tbuf) - TPM_HEADER_SIZE;
> + body_size = tpm_buf_length(tbuf) - TPM_HEADER_SIZE;
> if ((*offset + body_size) > buf_size) {
> dev_warn(&chip->dev, "%s: out of backing storage\n", __func__);
> - tpm_buf_destroy(&tbuf);
> return -ENOMEM;
> }
>
> - memcpy(&buf[*offset], &tbuf.data[TPM_HEADER_SIZE], body_size);
> + memcpy(&buf[*offset], &tbuf->data[TPM_HEADER_SIZE], body_size);
> *offset += body_size;
> - tpm_buf_destroy(&tbuf);
> return 0;
> }
>
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 0818bb517805..682dfc93845d 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -395,40 +395,36 @@ static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip *chip, u8 status)
>
> static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
> {
> - struct tpm_buf buf;
> int rc;
> const struct tpm_header *header;
> struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + tpm_buf_init(buf, TPM_BUFSIZE);
> if (chip->flags & TPM_CHIP_FLAG_TPM2)
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS,
> - TPM2_CC_SET_LOCALITY);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_SET_LOCALITY);
> else
> - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND,
> - TPM_ORD_SET_LOCALITY);
> - if (rc)
> - return rc;
> - tpm_buf_append_u8(&buf, locality);
> + tpm_buf_reset(buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SET_LOCALITY);
> +
> + tpm_buf_append_u8(buf, locality);
>
> proxy_dev->state |= STATE_DRIVER_COMMAND;
>
> - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to set locality");
> + rc = tpm_transmit_cmd(chip, buf, 0, "attempting to set locality");
>
> proxy_dev->state &= ~STATE_DRIVER_COMMAND;
>
> - if (rc < 0) {
> - locality = rc;
> - goto out;
> - }
> + if (rc < 0)
> + return rc;
>
> - header = (const struct tpm_header *)buf.data;
> + header = (const struct tpm_header *)buf->data;
> rc = be32_to_cpu(header->return_code);
> if (rc)
> locality = -1;
>
> -out:
> - tpm_buf_destroy(&buf);
> -
> return locality;
> }
>
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index 1e0585e45371..42e2a091f43d 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -25,7 +25,8 @@
> #include <crypto/hash_info.h>
> #include <crypto/aes.h>
>
> -#define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */
> +#define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */
> +#define TPM_BUFSIZE 4096
>
> #define TPM2_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE
> #define TPM2_MAX_PCR_BANKS 8
> @@ -376,13 +377,15 @@ enum tpm_buf_flags {
> };
>
> /*
> - * A string buffer type for constructing TPM commands.
> + * A buffer for constructing and parsing TPM commands, responses and sized
> + * (TPM2B) buffers.
> */
> struct tpm_buf {
> - u32 flags;
> - u32 length;
> - u8 *data;
> + u8 flags;
> u8 handles;
> + u16 length;
> + u16 capacity;
> + u8 data[];
> };
>
> enum tpm2_object_attributes {
> @@ -413,12 +416,11 @@ struct tpm2_hash {
> unsigned int tpm_id;
> };
>
> -int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);
> +void tpm_buf_init(struct tpm_buf *buf, u16 buf_size);
> +void tpm_buf_init_sized(struct tpm_buf *buf, u16 buf_size);
> void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);
> -int tpm_buf_init_sized(struct tpm_buf *buf);
> void tpm_buf_reset_sized(struct tpm_buf *buf);
> -void tpm_buf_destroy(struct tpm_buf *buf);
> -u32 tpm_buf_length(struct tpm_buf *buf);
> +u16 tpm_buf_length(struct tpm_buf *buf);
> void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length);
> void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value);
> void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value);
> diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
> index 636acb66a4f6..759c1ecb0435 100644
> --- a/security/keys/trusted-keys/trusted_tpm1.c
> +++ b/security/keys/trusted-keys/trusted_tpm1.c
> @@ -310,9 +310,10 @@ static int TSS_checkhmac2(unsigned char *buffer,
> * For key specific tpm requests, we will generate and send our
> * own TPM command packets using the drivers send function.
> */
> -static int trusted_tpm_send(unsigned char *cmd, size_t buflen)
> +static int trusted_tpm_send(void *cmd, size_t cmd_len)
> {
> - struct tpm_buf buf;
> + u8 buf_data[512];
> + struct tpm_buf *buf = (struct tpm_buf *)buf_data;
> int rc;
>
> if (!chip)
> @@ -322,11 +323,10 @@ static int trusted_tpm_send(unsigned char *cmd, size_t buflen)
> if (rc)
> return rc;
>
> - buf.flags = 0;
> - buf.length = buflen;
> - buf.data = cmd;
> + tpm_buf_init(buf, sizeof(buf_data));
> + tpm_buf_append(buf, cmd, cmd_len);
> dump_tpm_buf(cmd);
> - rc = tpm_transmit_cmd(chip, &buf, 4, "sending data");
> + rc = tpm_transmit_cmd(chip, buf, 4, "sending data");
> dump_tpm_buf(cmd);
>
> if (rc > 0)
> @@ -624,23 +624,23 @@ static int tpm_unseal(struct tpm_buf *tb,
> static int key_seal(struct trusted_key_payload *p,
> struct trusted_key_options *o)
> {
> - struct tpm_buf tb;
> int ret;
>
> - ret = tpm_buf_init(&tb, 0, 0);
> - if (ret)
> - return ret;
> + struct tpm_buf *tb __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!tb)
> + return -ENOMEM;
> +
> + tpm_buf_init(tb, TPM_BUFSIZE);
>
> /* 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, o->keyhandle, o->keyauth,
> p->key, p->key_len + 1, p->blob, &p->blob_len,
> o->blobauth, o->pcrinfo, o->pcrinfo_len);
> if (ret < 0)
> pr_info("srkseal failed (%d)\n", ret);
>
> - tpm_buf_destroy(&tb);
> return ret;
> }
>
> @@ -650,14 +650,15 @@ static int key_seal(struct trusted_key_payload *p,
> static int key_unseal(struct trusted_key_payload *p,
> struct trusted_key_options *o)
> {
> - struct tpm_buf tb;
> int ret;
>
> - ret = tpm_buf_init(&tb, 0, 0);
> - if (ret)
> - return ret;
> + struct tpm_buf *tb __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!tb)
> + return -ENOMEM;
> +
> + tpm_buf_init(tb, TPM_BUFSIZE);
>
> - ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
> + ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
> o->blobauth, p->key, &p->key_len);
> if (ret < 0)
> pr_info("srkunseal failed (%d)\n", ret);
> @@ -665,7 +666,6 @@ static int key_unseal(struct trusted_key_payload *p,
> /* pull migratable flag out of sealed key */
> p->migratable = p->key[--p->key_len];
>
> - tpm_buf_destroy(&tb);
> return ret;
> }
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index fdba641fefdb..fb76c4ea496f 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -234,7 +234,6 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> struct trusted_key_options *options)
> {
> off_t offset = TPM_HEADER_SIZE;
> - struct tpm_buf buf, sized;
> int blob_len = 0;
> int hash;
> u32 flags;
> @@ -255,97 +254,99 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> if (rc)
> goto out_put;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
> - if (rc) {
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf) {
> + rc = -ENOMEM;
> tpm2_end_auth_session(chip);
> goto out_put;
> }
>
> - rc = tpm_buf_init_sized(&sized);
> - if (rc) {
> - tpm_buf_destroy(&buf);
> - tpm2_end_auth_session(chip);
> - goto out_put;
> - }
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
>
> - rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
> + rc = tpm_buf_append_name(chip, buf, options->keyhandle, NULL);
> if (rc)
> - goto out;
> + goto out_put;
>
> - tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT,
> + tpm_buf_append_hmac_session(chip, buf, TPM2_SA_DECRYPT,
> options->keyauth, TPM_DIGEST_SIZE);
>
> + struct tpm_buf *sized __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!sized) {
> + rc = -ENOMEM;
> + tpm2_end_auth_session(chip);
> + goto out_put;
> + }
> +
> /* sensitive */
> - tpm_buf_append_u16(&sized, options->blobauth_len);
> + tpm_buf_init_sized(sized, TPM_BUFSIZE);
> + tpm_buf_append_u16(sized, options->blobauth_len);
>
> if (options->blobauth_len)
> - tpm_buf_append(&sized, options->blobauth, options->blobauth_len);
> + tpm_buf_append(sized, options->blobauth, options->blobauth_len);
>
> - tpm_buf_append_u16(&sized, payload->key_len);
> - tpm_buf_append(&sized, payload->key, payload->key_len);
> - tpm_buf_append(&buf, sized.data, sized.length);
> + tpm_buf_append_u16(sized, payload->key_len);
> + tpm_buf_append(sized, payload->key, payload->key_len);
> + tpm_buf_append(buf, sized->data, sized->length);
>
> /* public */
> - tpm_buf_reset_sized(&sized);
> - tpm_buf_append_u16(&sized, TPM_ALG_KEYEDHASH);
> - tpm_buf_append_u16(&sized, hash);
> + tpm_buf_init_sized(sized, TPM_BUFSIZE);
> + tpm_buf_append_u16(sized, TPM_ALG_KEYEDHASH);
> + tpm_buf_append_u16(sized, hash);
>
> /* key properties */
> flags = 0;
> flags |= options->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);
> + tpm_buf_append_u32(sized, flags);
>
> /* policy */
> - tpm_buf_append_u16(&sized, options->policydigest_len);
> + tpm_buf_append_u16(sized, options->policydigest_len);
> if (options->policydigest_len)
> - tpm_buf_append(&sized, options->policydigest, options->policydigest_len);
> + tpm_buf_append(sized, options->policydigest, options->policydigest_len);
>
> /* public parameters */
> - tpm_buf_append_u16(&sized, TPM_ALG_NULL);
> - tpm_buf_append_u16(&sized, 0);
> + tpm_buf_append_u16(sized, TPM_ALG_NULL);
> + tpm_buf_append_u16(sized, 0);
>
> - tpm_buf_append(&buf, sized.data, sized.length);
> + tpm_buf_append(buf, sized->data, sized->length);
>
> /* outside info */
> - tpm_buf_append_u16(&buf, 0);
> + tpm_buf_append_u16(buf, 0);
>
> /* creation PCR */
> - tpm_buf_append_u32(&buf, 0);
> + tpm_buf_append_u32(buf, 0);
>
> - if (buf.flags & TPM_BUF_INVALID) {
> + if (buf->flags & TPM_BUF_INVALID) {
> rc = -E2BIG;
> tpm2_end_auth_session(chip);
> goto out;
> }
>
> - rc = tpm_buf_fill_hmac_session(chip, &buf);
> + rc = tpm_buf_fill_hmac_session(chip, buf);
> if (rc)
> goto out;
>
> - rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
> - rc = tpm_buf_check_hmac_response(chip, &buf, rc);
> + rc = tpm_transmit_cmd(chip, buf, 4, "sealing data");
> + rc = tpm_buf_check_hmac_response(chip, buf, rc);
> if (rc)
> goto out;
>
> - blob_len = tpm_buf_read_u32(&buf, &offset);
> - if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_INVALID) {
> + blob_len = tpm_buf_read_u32(buf, &offset);
> + if (blob_len > MAX_BLOB_SIZE || buf->flags & TPM_BUF_INVALID) {
> rc = -E2BIG;
> goto out;
> }
> - if (buf.length - offset < blob_len) {
> + if (buf->length - offset < blob_len) {
> rc = -EFAULT;
> goto out;
> }
>
> - blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len);
> + blob_len = tpm2_key_encode(payload, options, &buf->data[offset], blob_len);
> if (blob_len < 0)
> rc = blob_len;
>
> out:
> - tpm_buf_destroy(&sized);
> - tpm_buf_destroy(&buf);
> -
> if (!rc)
> payload->blob_len = blob_len;
>
> @@ -373,7 +374,6 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> u32 *blob_handle)
> {
> u8 *blob_ref __free(kfree) = NULL;
> - struct tpm_buf buf;
> unsigned int private_len;
> unsigned int public_len;
> unsigned int blob_len;
> @@ -427,39 +427,38 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> if (rc)
> return rc;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
> - if (rc) {
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf) {
> tpm2_end_auth_session(chip);
> - return rc;
> + return -ENOMEM;
> }
>
> - rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
> + 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);
> if (rc)
> - goto out;
> + return rc;
>
> - tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth,
> + tpm_buf_append_hmac_session(chip, buf, 0, options->keyauth,
> TPM_DIGEST_SIZE);
>
> - tpm_buf_append(&buf, blob, blob_len);
> + tpm_buf_append(buf, blob, blob_len);
>
> - if (buf.flags & TPM_BUF_INVALID) {
> - rc = -E2BIG;
> + if (buf->flags & TPM_BUF_INVALID) {
> tpm2_end_auth_session(chip);
> - goto out;
> + return -E2BIG;
> }
>
> - rc = tpm_buf_fill_hmac_session(chip, &buf);
> + rc = tpm_buf_fill_hmac_session(chip, buf);
> if (rc)
> - goto out;
> + return rc;
>
> - rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
> - rc = tpm_buf_check_hmac_response(chip, &buf, rc);
> + rc = tpm_transmit_cmd(chip, buf, 4, "loading blob");
> + rc = tpm_buf_check_hmac_response(chip, buf, rc);
> if (!rc)
> *blob_handle = be32_to_cpup(
> - (__be32 *) &buf.data[TPM_HEADER_SIZE]);
> -
> -out:
> - tpm_buf_destroy(&buf);
> + (__be32 *)&buf->data[TPM_HEADER_SIZE]);
>
> return tpm_ret_to_err(rc);
> }
> @@ -482,28 +481,28 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
> u32 blob_handle)
> {
> struct tpm_header *head;
> - struct tpm_buf buf;
> u16 data_len;
> int offset;
> u8 *data;
> int rc;
>
> + struct tpm_buf *buf __free(kfree) = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> rc = tpm2_start_auth_session(chip);
> if (rc)
> return rc;
>
> - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
> - if (rc) {
> - tpm2_end_auth_session(chip);
> - return rc;
> - }
> + tpm_buf_init(buf, TPM_BUFSIZE);
> + tpm_buf_reset(buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
>
> - rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
> + rc = tpm_buf_append_name(chip, buf, options->keyhandle, NULL);
> if (rc)
> - goto out;
> + return rc;
>
> if (!options->policyhandle) {
> - tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT,
> + tpm_buf_append_hmac_session(chip, buf, TPM2_SA_ENCRYPT,
> options->blobauth,
> options->blobauth_len);
> } else {
> @@ -518,39 +517,36 @@ 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, options->policyhandle,
> NULL /* nonce */, 0, 0,
> options->blobauth, options->blobauth_len);
> +
> if (tpm2_chip_auth(chip)) {
> - tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, NULL, 0);
> + tpm_buf_append_hmac_session(chip, buf, TPM2_SA_ENCRYPT, NULL, 0);
> } else {
> - offset = buf.handles * 4 + TPM_HEADER_SIZE;
> - head = (struct tpm_header *)buf.data;
> - if (tpm_buf_length(&buf) == offset)
> + offset = buf->handles * 4 + TPM_HEADER_SIZE;
> + head = (struct tpm_header *)buf->data;
> + if (tpm_buf_length(buf) == offset)
> head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
> }
> }
>
> - rc = tpm_buf_fill_hmac_session(chip, &buf);
> + rc = tpm_buf_fill_hmac_session(chip, buf);
> if (rc)
> - goto out;
> + return rc;
>
> - rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
> - rc = tpm_buf_check_hmac_response(chip, &buf, rc);
> + rc = tpm_transmit_cmd(chip, buf, 6, "unsealing");
> + rc = tpm_buf_check_hmac_response(chip, buf, rc);
>
> if (!rc) {
> data_len = be16_to_cpup(
> - (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
> - if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE) {
> - rc = -EFAULT;
> - goto out;
> - }
> + (__be16 *)&buf->data[TPM_HEADER_SIZE + 4]);
> + if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE)
> + return -EFAULT;
>
> - if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
> - rc = -EFAULT;
> - goto out;
> - }
> - data = &buf.data[TPM_HEADER_SIZE + 6];
> + if (tpm_buf_length(buf) < TPM_HEADER_SIZE + 6 + data_len)
> + return -EFAULT;
> + data = &buf->data[TPM_HEADER_SIZE + 6];
>
> if (payload->old_format) {
> /* migratable flag is at the end of the key */
> @@ -567,8 +563,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
> }
> }
>
> -out:
> - tpm_buf_destroy(&buf);
> return tpm_ret_to_err(rc);
> }
>
> --
> 2.39.5
>
I applied these patches to my master branch for these reasons:
1. It is a change for better, as managed allocations objectively
deliver safer memory semantics overall.
2. The patch has been in my testing cycle for months now already.
I've tested *everything* with it and without it in order to
stress the change a bit.
3. Despite being large change it does fit to the "single logical
change" category. It would only make things more dissolved if
it was split in any possible way.
4. It's a great idea roughly base it on 6.19-rc1 so that it can
be applied easily top of the mainline release (if wanted).
I will appreciate any testing results etc. and stay put on fixing
any possible issues. Also, e.g. tested-by tags can be added up
until the first pull request for 6.20.
BR, Jarkko
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