On Mon, Sep 29, 2025 at 10:48:27PM +0300, Jarkko Sakkinen wrote: > From: Jarkko Sakkinen <[email protected]> > > Open code tpm_buf_append_hmac_session_opt() in order to unmask the code > paths in the call sites of tpm_buf_append_hmac_session(). > > Signed-off-by: Jarkko Sakkinen <[email protected]>
Reviewed-by: Jonathan McDowell <[email protected]> > --- > v3: > - No changes. > v2: > - Uncorrupt the patch. > --- > drivers/char/tpm/tpm2-cmd.c | 14 +++++++++++--- > include/linux/tpm.h | 23 ----------------------- > security/keys/trusted-keys/trusted_tpm2.c | 12 ++++++++++-- > 3 files changed, 21 insertions(+), 28 deletions(-) > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 86b1a4d859b9..c7bfa705ea8f 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -257,9 +257,17 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, > size_t max) > > do { > tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM); > - tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT > - | TPM2_SA_CONTINUE_SESSION, > - NULL, 0); > + if (tpm2_chip_auth(chip)) { > + 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) > + head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); > + } > tpm_buf_append_u16(&buf, num_bytes); > tpm_buf_fill_hmac_session(chip, &buf); > err = tpm_transmit_cmd(chip, &buf, > diff --git a/include/linux/tpm.h b/include/linux/tpm.h > index 1fa02e18e688..e72e7657faa2 100644 > --- a/include/linux/tpm.h > +++ b/include/linux/tpm.h > @@ -532,29 +532,6 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, > struct tpm_buf *buf, > int passphraselen); > void tpm_buf_append_auth(struct tpm_chip *chip, struct tpm_buf *buf, > u8 *passphrase, int passphraselen); > -static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip, > - struct tpm_buf *buf, > - u8 attributes, > - u8 *passphrase, > - int passphraselen) > -{ > - struct tpm_header *head; > - int offset; > - > - if (tpm2_chip_auth(chip)) { > - tpm_buf_append_hmac_session(chip, buf, attributes, passphrase, > passphraselen); > - } else { > - offset = buf->handles * 4 + TPM_HEADER_SIZE; > - head = (struct tpm_header *)buf->data; > - > - /* > - * If the only sessions are optional, the command tag must > change to > - * TPM2_ST_NO_SESSIONS. > - */ > - if (tpm_buf_length(buf) == offset) > - head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); > - } > -} > > #ifdef CONFIG_TCG_TPM2_HMAC > > diff --git a/security/keys/trusted-keys/trusted_tpm2.c > b/security/keys/trusted-keys/trusted_tpm2.c > index e165b117bbca..c414a7006d78 100644 > --- a/security/keys/trusted-keys/trusted_tpm2.c > +++ b/security/keys/trusted-keys/trusted_tpm2.c > @@ -482,8 +482,10 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, > struct trusted_key_options *options, > u32 blob_handle) > { > + struct tpm_header *head; > struct tpm_buf buf; > u16 data_len; > + int offset; > u8 *data; > int rc; > > @@ -518,8 +520,14 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, > tpm2_buf_append_auth(&buf, options->policyhandle, > NULL /* nonce */, 0, 0, > options->blobauth, options->blobauth_len); > - tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT, > - NULL, 0); > + if (tpm2_chip_auth(chip)) { > + 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) > + head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); > + } > } > > tpm_buf_fill_hmac_session(chip, &buf); > -- > 2.39.5 > > J. -- ... I love you the way a bomb loves a crowd.
