| Message ID | 20240701170735.109583-1-jarkko@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | tpm: Check non-nullity of chip->auth | expand |
On 7/1/24 13:07, Jarkko Sakkinen wrote: > All exported functions lack the check for non-nullity of chip->auth. Add > the guard for each. > > Link: https://lore.kernel.org/linux-integrity/9f86a167074d9b522311715c567f1c19b88e3ad4.camel@kernel.org/ > Cc: Stefan Berger <stefanb@linux.ibm.com> > Cc: stable@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Fixes: 1085b8276bb4 ("tpm: Add the rest of the session HMAC API") > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> > --- > drivers/char/tpm/tpm2-sessions.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c > index 907ac9956a78..d833db20531a 100644 > --- a/drivers/char/tpm/tpm2-sessions.c > +++ b/drivers/char/tpm/tpm2-sessions.c > @@ -377,6 +377,9 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, > u32 len; > struct tpm2_auth *auth = chip->auth; > > + if (!auth) > + return; > + > /* > * The Architecture Guide requires us to strip trailing zeros > * before computing the HMAC > @@ -449,6 +452,9 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) > u8 cphash[SHA256_DIGEST_SIZE]; > struct sha256_state sctx; > > + if (!auth) > + return; > + > /* save the command code in BE format */ > auth->ordinal = head->ordinal; > > @@ -639,6 +645,9 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, > struct tpm2_auth *auth = chip->auth; > int slot; > > + if (!auth) > + return; > + > slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE)/4; > if (slot >= AUTH_MAX_NAMES) { > dev_err(&chip->dev, "TPM: too many handles\n"); > @@ -705,6 +714,9 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, > u32 cc = be32_to_cpu(auth->ordinal); > int parm_len, len, i, handles; > > + if (!auth) > + return rc; > + > if (auth->session >= TPM_HEADER_SIZE) { > WARN(1, "tpm session not filled correctly\n"); > goto out; > @@ -824,8 +836,13 @@ EXPORT_SYMBOL(tpm_buf_check_hmac_response); > */ > void tpm2_end_auth_session(struct tpm_chip *chip) > { > - tpm2_flush_context(chip, chip->auth->handle); > - memzero_explicit(chip->auth, sizeof(*chip->auth)); > + struct tpm2_auth *auth = chip->auth; > + > + if (!auth) > + return; > + > + tpm2_flush_context(chip, auth->handle); > + memzero_explicit(auth, sizeof(*auth)); > } > EXPORT_SYMBOL(tpm2_end_auth_session); > > @@ -907,6 +924,11 @@ int tpm2_start_auth_session(struct tpm_chip *chip) > int rc; > u32 null_key; > > + if (!auth) { > + pr_warn_once("%s: encryption is not active\n", __func__); > + return 0; > + } > + > rc = tpm2_load_null(chip, &null_key); > if (rc) > goto out; It looks like you got all of the chip->auth tested: Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> As I mentioned in the other email (1), it does not solve the problem on ppc64. 1: https://lore.kernel.org/linux-integrity/656b319fc58683e399323b880722434467cf20f2.camel@kernel.org/T/#m88892cb6f9cf8fdef875dcdd0ed3eccac1d28190
diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 907ac9956a78..d833db20531a 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -377,6 +377,9 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, u32 len; struct tpm2_auth *auth = chip->auth; + if (!auth) + return; + /* * The Architecture Guide requires us to strip trailing zeros * before computing the HMAC @@ -449,6 +452,9 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) u8 cphash[SHA256_DIGEST_SIZE]; struct sha256_state sctx; + if (!auth) + return; + /* save the command code in BE format */ auth->ordinal = head->ordinal; @@ -639,6 +645,9 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, struct tpm2_auth *auth = chip->auth; int slot; + if (!auth) + return; + slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE)/4; if (slot >= AUTH_MAX_NAMES) { dev_err(&chip->dev, "TPM: too many handles\n"); @@ -705,6 +714,9 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, u32 cc = be32_to_cpu(auth->ordinal); int parm_len, len, i, handles; + if (!auth) + return rc; + if (auth->session >= TPM_HEADER_SIZE) { WARN(1, "tpm session not filled correctly\n"); goto out; @@ -824,8 +836,13 @@ EXPORT_SYMBOL(tpm_buf_check_hmac_response); */ void tpm2_end_auth_session(struct tpm_chip *chip) { - tpm2_flush_context(chip, chip->auth->handle); - memzero_explicit(chip->auth, sizeof(*chip->auth)); + struct tpm2_auth *auth = chip->auth; + + if (!auth) + return; + + tpm2_flush_context(chip, auth->handle); + memzero_explicit(auth, sizeof(*auth)); } EXPORT_SYMBOL(tpm2_end_auth_session); @@ -907,6 +924,11 @@ int tpm2_start_auth_session(struct tpm_chip *chip) int rc; u32 null_key; + if (!auth) { + pr_warn_once("%s: encryption is not active\n", __func__); + return 0; + } + rc = tpm2_load_null(chip, &null_key); if (rc) goto out;
All exported functions lack the check for non-nullity of chip->auth. Add the guard for each. Link: https://lore.kernel.org/linux-integrity/9f86a167074d9b522311715c567f1c19b88e3ad4.camel@kernel.org/ Cc: Stefan Berger <stefanb@linux.ibm.com> Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 1085b8276bb4 ("tpm: Add the rest of the session HMAC API") Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> --- drivers/char/tpm/tpm2-sessions.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-)