> 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));
>
> Reviewed-by: Stefan Berger <[email protected]>
> Signed-off-by: Jarkko Sakkinen <[email protected]>
> ---
> v3:
> - A new patch from the earlier series with more scoped changes and
> less abstract commit message.
> ---
> drivers/char/tpm/tpm-buf.c | 122 +++++----
> drivers/char/tpm/tpm-sysfs.c | 20 +-
> drivers/char/tpm/tpm.h | 1 -
> drivers/char/tpm/tpm1-cmd.c | 147 +++++------
> drivers/char/tpm/tpm2-cmd.c | 290 ++++++++++------------
> drivers/char/tpm/tpm2-sessions.c | 121 +++++----
> drivers/char/tpm/tpm2-space.c | 44 ++--
> drivers/char/tpm/tpm_vtpm_proxy.c | 30 +--
> include/linux/tpm.h | 18 +-
> security/keys/trusted-keys/trusted_tpm1.c | 34 ++-
> security/keys/trusted-keys/trusted_tpm2.c | 176 ++++++-------
> 11 files changed, 482 insertions(+), 521 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index c9e6e5d097ca..1cb649938c01 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
> @@ -92,6 +119,9 @@ EXPORT_SYMBOL_GPL(tpm_buf_destroy);
> */
> u32 tpm_buf_length(struct tpm_buf *buf)
Should we update the return value to u16?
> {
> + 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/security/keys/trusted-keys/trusted_tpm1.c
b/security/keys/trusted-keys/trusted_tpm1.c
> index 636acb66a4f6..6e6a9fb48e63 100644
> --- a/security/keys/trusted-keys/trusted_tpm1.c
> +++ b/security/keys/trusted-keys/trusted_tpm1.c
> @@ -310,9 +310,8 @@ 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 buflen)
> {
> - struct tpm_buf buf;
> int rc;
>
> if (!chip)
> @@ -322,15 +321,12 @@ static int trusted_tpm_send(unsigned char *cmd, size_t
buflen)
> if (rc)
> return rc;
>
> - buf.flags = 0;
> - buf.length = buflen;
> - buf.data = cmd;
> dump_tpm_buf(cmd);
> - rc = tpm_transmit_cmd(chip, &buf, 4, "sending data");
> + rc = tpm_transmit_cmd(chip, cmd, 4, "sending data");
Is it fine here to remove the intermediate tpm_buf ?
IIUC tpm_transmit_cmd() needs a tpm_buf, while here we are passing just
the "data", or in some way it's a nested tpm_buf?
(Sorry if it's a stupid question, but I'm still a bit new with this code).
> dump_tpm_buf(cmd);
>
> + /* Convert TPM error to -EPERM. */
> if (rc > 0)
> - /* TPM error */
> rc = -EPERM;
>
> tpm_put_ops(chip);
> @@ -624,23 +620,23 @@ 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(PAGE_SIZE, 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 +646,15 @@ 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(PAGE_SIZE, 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 +662,6 @@ 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;
> }
The rest LGTM, but it's a huge patch (not your issue at all), so yeah not
sure :-)
