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Hallyn" , Dmitry Kasatkin , Eric Snowberg , "open list:KEYS-TRUSTED" , "open list:SECURITY SUBSYSTEM" , Pengyu Ma , stable@vger.kernel.org References: <20241028055007.1708971-1-jarkko@kernel.org> <20241028055007.1708971-4-jarkko@kernel.org> Content-Language: en-US From: Stefan Berger In-Reply-To: <20241028055007.1708971-4-jarkko@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 8QHMdygOQ_15fX3jEs9sEBGPXVZQ6f7s X-Proofpoint-GUID: jEwr1Tf097hsjt9C9ZN8DzkfL1ixeTK2 Content-Transfer-Encoding: 7bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 adultscore=0 impostorscore=0 priorityscore=1501 clxscore=1015 bulkscore=0 mlxscore=0 lowpriorityscore=0 phishscore=0 suspectscore=0 spamscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410280134 On 10/28/24 1:50 AM, Jarkko Sakkinen wrote: > Move the allocation of chip->auth to tpm2_start_auth_session() so that this > field can be used as flag to tell whether auth session is active or not. > > Instead of flushing and reloading the auth session for every transaction > separately, keep the session open unless /dev/tpm0 is used. > > Reported-by: Pengyu Ma > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219229 > Cc: stable@vger.kernel.org # v6.10+ > Fixes: 7ca110f2679b ("tpm: Address !chip->auth in tpm_buf_append_hmac_session*()") > Tested-by: Pengyu Ma > Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger Tested-by: Stefan Berger > --- > v8: > - Since auth session and null key are flushed at a same time, only > either needs to be checked. Addresses and a remark from James > Bottomley few revisions ago. > - kfree_sensitive() > - Effectively squash top three patches given the simplifications. > v7: > - No changes. > v6: > - No changes. > v5: > - No changes. > v4: > - Changed as bug. > v3: > - Refined the commit message. > - Removed the conditional for applying TPM2_SA_CONTINUE_SESSION only when > /dev/tpm0 is open. It is not required as the auth session is flushed, > not saved. > v2: > - A new patch. > --- > drivers/char/tpm/tpm-chip.c | 10 +++++++ > drivers/char/tpm/tpm-dev-common.c | 3 +++ > drivers/char/tpm/tpm-interface.c | 6 +++-- > drivers/char/tpm/tpm2-sessions.c | 45 ++++++++++++++++++------------- > 4 files changed, 44 insertions(+), 20 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index 854546000c92..1ff99a7091bb 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -674,6 +674,16 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); > */ > void tpm_chip_unregister(struct tpm_chip *chip) > { > +#ifdef CONFIG_TCG_TPM2_HMAC > + int rc; > + > + rc = tpm_try_get_ops(chip); > + if (!rc) { > + tpm2_end_auth_session(chip); > + tpm_put_ops(chip); > + } > +#endif > + > tpm_del_legacy_sysfs(chip); > if (tpm_is_hwrng_enabled(chip)) > hwrng_unregister(&chip->hwrng); > diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c > index 30b4c288c1bb..c7a88fa7b0fc 100644 > --- a/drivers/char/tpm/tpm-dev-common.c > +++ b/drivers/char/tpm/tpm-dev-common.c > @@ -27,6 +27,9 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space, > struct tpm_header *header = (void *)buf; > ssize_t ret, len; > > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > + tpm2_end_auth_session(chip); > + > ret = tpm2_prepare_space(chip, space, buf, bufsiz); > /* If the command is not implemented by the TPM, synthesize a > * response with a TPM2_RC_COMMAND_CODE return for user-space. > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 5da134f12c9a..8134f002b121 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -379,10 +379,12 @@ int tpm_pm_suspend(struct device *dev) > > rc = tpm_try_get_ops(chip); > if (!rc) { > - if (chip->flags & TPM_CHIP_FLAG_TPM2) > + if (chip->flags & TPM_CHIP_FLAG_TPM2) { > + tpm2_end_auth_session(chip); > tpm2_shutdown(chip, TPM2_SU_STATE); > - else > + } else { > rc = tpm1_pm_suspend(chip, tpm_suspend_pcr); > + } > > tpm_put_ops(chip); > } > diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c > index 950a3e48293b..03145a465b5d 100644 > --- a/drivers/char/tpm/tpm2-sessions.c > +++ b/drivers/char/tpm/tpm2-sessions.c > @@ -333,6 +333,9 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, > } > > #ifdef CONFIG_TCG_TPM2_HMAC > + /* The first write to /dev/tpm{rm0} will flush the session. */ > + attributes |= TPM2_SA_CONTINUE_SESSION; > + > /* > * The Architecture Guide requires us to strip trailing zeros > * before computing the HMAC > @@ -484,7 +487,8 @@ static void tpm2_KDFe(u8 z[EC_PT_SZ], const char *str, u8 *pt_u, u8 *pt_v, > sha256_final(&sctx, out); > } > > -static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) > +static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip, > + struct tpm2_auth *auth) > { > struct crypto_kpp *kpp; > struct kpp_request *req; > @@ -543,7 +547,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) > sg_set_buf(&s[0], chip->null_ec_key_x, EC_PT_SZ); > sg_set_buf(&s[1], chip->null_ec_key_y, EC_PT_SZ); > kpp_request_set_input(req, s, EC_PT_SZ*2); > - sg_init_one(d, chip->auth->salt, EC_PT_SZ); > + sg_init_one(d, auth->salt, EC_PT_SZ); > kpp_request_set_output(req, d, EC_PT_SZ); > crypto_kpp_compute_shared_secret(req); > kpp_request_free(req); > @@ -554,8 +558,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) > * This works because KDFe fully consumes the secret before it > * writes the salt > */ > - tpm2_KDFe(chip->auth->salt, "SECRET", x, chip->null_ec_key_x, > - chip->auth->salt); > + tpm2_KDFe(auth->salt, "SECRET", x, chip->null_ec_key_x, auth->salt); > > out: > crypto_free_kpp(kpp); > @@ -853,7 +856,9 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, > if (rc) > /* manually close the session if it wasn't consumed */ > tpm2_flush_context(chip, auth->handle); > - memzero_explicit(auth, sizeof(*auth)); > + > + kfree_sensitive(auth); > + chip->auth = NULL; > } else { > /* reset for next use */ > auth->session = TPM_HEADER_SIZE; > @@ -881,7 +886,8 @@ void tpm2_end_auth_session(struct tpm_chip *chip) > return; > > tpm2_flush_context(chip, auth->handle); > - memzero_explicit(auth, sizeof(*auth)); > + kfree_sensitive(auth); > + chip->auth = NULL; > } > EXPORT_SYMBOL(tpm2_end_auth_session); > > @@ -962,16 +968,20 @@ 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; > - struct tpm2_auth *auth = chip->auth; > - int rc; > u32 null_key; > + int rc; > > - if (!auth) { > - dev_warn_once(&chip->dev, "auth session is not active\n"); > + if (chip->auth) { > + dev_warn_once(&chip->dev, "auth session is active\n"); > return 0; > } > > + auth = kzalloc(sizeof(*auth), GFP_KERNEL); > + if (!auth) > + return -ENOMEM; > + > rc = tpm2_load_null(chip, &null_key); > if (rc) > goto out; > @@ -992,7 +1002,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip) > 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); > + tpm_buf_append_salt(&buf, chip, auth); > /* session type (HMAC, audit or policy) */ > tpm_buf_append_u8(&buf, TPM2_SE_HMAC); > > @@ -1014,10 +1024,13 @@ int tpm2_start_auth_session(struct tpm_chip *chip) > > tpm_buf_destroy(&buf); > > - if (rc) > - goto out; > + if (rc == TPM2_RC_SUCCESS) { > + chip->auth = auth; > + return 0; > + } > > - out: > +out: > + kfree_sensitive(auth); > return rc; > } > EXPORT_SYMBOL(tpm2_start_auth_session); > @@ -1367,10 +1380,6 @@ int tpm2_sessions_init(struct tpm_chip *chip) > return rc; > } > > - chip->auth = kmalloc(sizeof(*chip->auth), GFP_KERNEL); > - if (!chip->auth) > - return -ENOMEM; > - > return rc; > } > #endif /* CONFIG_TCG_TPM2_HMAC */