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Commit 7d761119 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

tpm: fix RC value check in tpm2_seal_trusted 



The error code handling is broken as any error code that has the same
bits set as TPM_RC_HASH passes. Implemented tpm2_rc_value() helper to
parse the error value from FMT0 and FMT1 error codes so that these types
of mistakes are prevented in the future.

Fixes: 5ca4c20c ("keys, trusted: select hash algorithm for TPM2 chips")
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
parent 419a16d9

drivers/char/tpm/tpm.h

+5 −0
Original line number Diff line number Diff line
@@ -519,6 +519,11 @@ static inline void tpm_add_ppi(struct tpm_chip *chip) 
}

#endif



static inline inline u32 tpm2_rc_value(u32 rc)

{

	return (rc & BIT(7)) ? rc & 0xff : rc;

}



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, const u8 *hash);

int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);

drivers/char/tpm/tpm2-cmd.c

+1 −1
Original line number Diff line number Diff line
@@ -546,7 +546,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
	tpm_buf_destroy(&buf);



	if (rc > 0) {

		if ((rc & TPM2_RC_HASH) == TPM2_RC_HASH)

		if (tpm2_rc_value(rc) == TPM2_RC_HASH)

			rc = -EINVAL;

		else

			rc = -EPERM;