[PATCH v7 21/21] tpm: use u32 instead of int for PCR index

Winkler, Tomas tomas.winkler at intel.com
Tue Oct 23 18:56:24 UTC 2018


> 
> On Fri, 19 Oct 2018, Tomas Winkler wrote:
> > The TPM specs defines PCR index as a positive number, and there is no
> > reason to use a signed number. It is also a possible security issue as
> > currently no functions check for a negative index, which may become a
> > large number when converted to u32.
> >
> > Adjust the API to use u32 instead of int in all PCR related functions.
> >
> > Signed-off-by: Tomas Winkler <tomas.winkler at intel.com>
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
> > Tested-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
> > ---
> > V3: New in the series.
> > V4: Separate unrelated change to another patches.
> > V5: Fix the commit message.
> > V6: Rebased.
> > V7: Resend.
> >
> > drivers/char/tpm/tpm-interface.c    |  6 +++---
> > drivers/char/tpm/tpm-sysfs.c        |  2 +-
> > drivers/char/tpm/tpm.h              | 10 +++++-----
> > drivers/char/tpm/tpm1-cmd.c         |  6 +++---
> > drivers/char/tpm/tpm2-cmd.c         |  5 ++---
> > include/linux/tpm.h                 | 11 +++++++----
> > security/integrity/ima/ima_crypto.c |  5 +++--
> > 7 files changed, 24 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm-interface.c
> > b/drivers/char/tpm/tpm-interface.c
> > index acd647476ae1..d9439f9abe78 100644
> > --- a/drivers/char/tpm/tpm-interface.c
> > +++ b/drivers/char/tpm/tpm-interface.c
> > @@ -38,7 +38,7 @@
> >  * recently changed pcr on suspend, so force the flush
> >  * with an extend to the selected _unused_ non-volatile pcr.
> >  */
> > -static int tpm_suspend_pcr;
> > +static u32 tpm_suspend_pcr;
> > module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
> > MODULE_PARM_DESC(suspend_pcr,
> > 		 "PCR to use for dummy writes to facilitate flush on
> suspend."); @@
> > -455,7 +455,7 @@ EXPORT_SYMBOL_GPL(tpm_is_tpm2);
> >  *
> >  * Return: same as with tpm_transmit_cmd()  */ -int
> > tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
> > +int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> > {
> > 	int rc;
> >
> > @@ -485,7 +485,7 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read);
> >  *
> >  * Return: same as with tpm_transmit_cmd()  */ -int
> > tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
> > +int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8
> > +*hash)
> > {
> > 	int rc;
> > 	struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
> > diff --git a/drivers/char/tpm/tpm-sysfs.c
> > b/drivers/char/tpm/tpm-sysfs.c index 96fc7433c57d..b88e08ec2c59 100644
> > --- a/drivers/char/tpm/tpm-sysfs.c
> > +++ b/drivers/char/tpm/tpm-sysfs.c
> > @@ -102,7 +102,7 @@ static ssize_t pcrs_show(struct device *dev, struct
> device_attribute *attr,
> > 	cap_t cap;
> > 	u8 digest[TPM_DIGEST_SIZE];
> > 	ssize_t rc;
> > -	int i, j, num_pcrs;
> > +	u32 i, j, num_pcrs;
> > 	char *str = buf;
> > 	struct tpm_chip *chip = to_tpm_chip(dev);
> >
> > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index
> > e0778d19da98..f27d1f38a93d 100644
> > --- a/drivers/char/tpm/tpm.h
> > +++ b/drivers/char/tpm/tpm.h
> > @@ -509,14 +509,14 @@ ssize_t tpm_transmit_cmd(struct tpm_chip
> *chip,
> > struct tpm_space *space, int tpm_get_timeouts(struct tpm_chip *); int
> > tpm_auto_startup(struct tpm_chip *chip);
> >
> > -int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr);
> > +int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr);
> > int tpm1_auto_startup(struct tpm_chip *chip); int
> > tpm1_do_selftest(struct tpm_chip *chip); int tpm1_get_timeouts(struct
> > tpm_chip *chip); unsigned long tpm1_calc_ordinal_duration(struct
> > tpm_chip *chip, u32 ordinal); -int tpm1_pcr_extend(struct tpm_chip
> > *chip, int pcr_idx, const u8 *hash,
> > +int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8
> > +*hash,
> > 		    const char *log_msg);
> > -int tpm1_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
> > +int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
> > ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> > 		    const char *desc, size_t min_cap_length); int
> > tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max); @@ -558,8
> > +558,8 @@ static inline u32 tpm2_rc_value(u32 rc) }
> >
> > int tpm2_get_timeouts(struct tpm_chip *chip); -int
> > tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf); -int
> > tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
> > +int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
> > +int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
> > 		    struct tpm2_digest *digests);
> > int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); void
> > tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle, diff --git
> > a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index
> > 6b04648f8184..6f306338953b 100644
> > --- a/drivers/char/tpm/tpm1-cmd.c
> > +++ b/drivers/char/tpm/tpm1-cmd.c
> > @@ -449,7 +449,7 @@ int tpm1_get_timeouts(struct tpm_chip *chip) }
> >
> > #define TPM_ORD_PCR_EXTEND 20
> > -int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8
> > *hash,
> > +int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8
> > +*hash,
> > 		    const char *log_msg)
> > {
> > 	struct tpm_buf buf;
> > @@ -572,7 +572,7 @@ int tpm1_get_random(struct tpm_chip *chip, u8
> > *dest, size_t max) }
> >
> > #define TPM_ORD_PCRREAD 21
> > -int tpm1_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
> > +int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> > {
> > 	struct tpm_buf buf;
> > 	int rc;
> > @@ -729,7 +729,7 @@ int tpm1_auto_startup(struct tpm_chip *chip)
> >  * * 0 on success,
> >  * * < 0 on error.
> >  */
> > -int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr)
> > +int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
> > {
> > 	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
> > 	struct tpm_buf buf;
> > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> > index 6ca4fc0a0d6f..ae86fb0218ab 100644
> > --- a/drivers/char/tpm/tpm2-cmd.c
> > +++ b/drivers/char/tpm/tpm2-cmd.c
> > @@ -175,7 +175,7 @@ struct tpm2_pcr_read_out {
> >  *
> >  * Return: Same as with tpm_transmit_cmd.
> >  */
> > -int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
> > +int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> > {
> > 	int rc;
> > 	struct tpm_buf buf;
> > @@ -225,7 +225,7 @@ struct tpm2_null_auth_area {
> >  *
> >  * Return: Same as with tpm_transmit_cmd.
> >  */
> > -int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
> > +int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
> > 		    struct tpm2_digest *digests)
> > {
> > 	struct tpm_buf buf;
> > @@ -272,7 +272,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int
> pcr_idx, u32 count,
> > 	return rc;
> > }
> >
> > -
> > struct tpm2_get_random_out {
> > 	__be16 size;
> > 	u8 buffer[TPM_MAX_RNG_DATA];
> > diff --git a/include/linux/tpm.h b/include/linux/tpm.h index
> > 4609b94142d4..b49a55cf775f 100644
> > --- a/include/linux/tpm.h
> > +++ b/include/linux/tpm.h
> > @@ -53,8 +53,8 @@ struct tpm_class_ops { #if defined(CONFIG_TCG_TPM)
> > || defined(CONFIG_TCG_TPM_MODULE)
> >
> > extern int tpm_is_tpm2(struct tpm_chip *chip); -extern int
> > tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf); -extern
> > int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8
> > *hash);
> > +extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8
> > +*res_buf); extern int tpm_pcr_extend(struct tpm_chip *chip, u32
> > +pcr_idx, const u8 *hash);
> > extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen);
> > extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t
> > max); extern int tpm_seal_trusted(struct tpm_chip *chip, @@ -69,15
> > +69,18 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip) {
> > 	return -ENODEV;
> > }
> > -static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8
> > *res_buf)
> > +
> > +static inline int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8
> > +*res_buf)
> > {
> > 	return -ENODEV;
> > }
> > -static inline int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx,
> > +
> > +static inline int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> > 				 const u8 *hash)
> > {
> > 	return -ENODEV;
> > }
> > +
> > static inline int tpm_send(struct tpm_chip *chip, void *cmd, size_t
> > buflen) {
> > 	return -ENODEV;
> > diff --git a/security/integrity/ima/ima_crypto.c
> > b/security/integrity/ima/ima_crypto.c
> > index 7e7e7e7c250a..959d9edc113a 100644
> > --- a/security/integrity/ima/ima_crypto.c
> > +++ b/security/integrity/ima/ima_crypto.c
> > @@ -629,7 +629,7 @@ int ima_calc_buffer_hash(const void *buf, loff_t
> len,
> > 	return calc_buffer_shash(buf, len, hash); }
> >
> > -static void __init ima_pcrread(int idx, u8 *pcr)
> > +static void __init ima_pcrread(u32 idx, u8 *pcr)
> > {
> > 	if (!ima_tpm_chip)
> > 		return;
> > @@ -645,7 +645,8 @@ static int __init ima_calc_boot_aggregate_tfm(char
> *digest,
> > 					      struct crypto_shash *tfm)
> > {
> > 	u8 pcr_i[TPM_DIGEST_SIZE];
> > -	int rc, i;
> > +	int rc;
> > +	u32 i;
> > 	SHASH_DESC_ON_STACK(shash, tfm);
> >
> > 	shash->tfm = tfm;
> >
> 
> All commits have been now applied.
> 
Appreciated.
Thanks
Tomas



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