diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-30 12:17:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-30 12:17:21 -0700 |
| commit | b13f40bc69a16e465d21e23ca5adf4bf26365815 (patch) | |
| tree | 0c4594e40a12600129ff43575de282f9a4a64658 | |
| parent | 7c30b859a947535f2213277e827d7ac7dcff9c84 (diff) | |
| parent | 20c59ce010f84300f6c655d32db2610d3433f85c (diff) | |
Merge tag 'integrity-v5.8-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Include PCRs 8 & 9 in per TPM 2.0 bank boot_aggregate calculation.
Prior to Linux 5.8 the SHA1 "boot_aggregate" value was padded with 0's
and extended into the other TPM 2.0 banks.
Included in the Linux 5.8 open window, TPM 2.0 PCR bank specific
"boot_aggregate" values (PCRs 0 - 7) are calculated and extended into the TPM banks.
Distro releases are now shipping grub2 with TPM support, which extend
PCRs 8 & 9. I'd like for PCRs 8 & 9 to be included in the new
"boot_aggregate" calculations.
For backwards compatibility, if the hash is SHA1, these new PCRs are
not included in the boot aggregate"
* tag 'integrity-v5.8-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: extend boot_aggregate with kernel measurements
| -rw-r--r-- | security/integrity/ima/ima.h | 2 | ||||
| -rw-r--r-- | security/integrity/ima/ima_crypto.c | 15 |
2 files changed, 15 insertions, 2 deletions
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index df93ac258e01..9d94080bdad8 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -30,7 +30,7 @@ enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; -enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; +enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 }; /* digest size for IMA, fits SHA1 or MD5 */ #define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 220b14920c37..011c3c76af86 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -823,13 +823,26 @@ static int ima_calc_boot_aggregate_tfm(char *digest, u16 alg_id, if (rc != 0) return rc; - /* cumulative sha1 over tpm registers 0-7 */ + /* cumulative digest over TPM registers 0-7 */ for (i = TPM_PCR0; i < TPM_PCR8; i++) { ima_pcrread(i, &d); /* now accumulate with current aggregate */ rc = crypto_shash_update(shash, d.digest, crypto_shash_digestsize(tfm)); } + /* + * Extend cumulative digest over TPM registers 8-9, which contain + * measurement for the kernel command line (reg. 8) and image (reg. 9) + * in a typical PCR allocation. Registers 8-9 are only included in + * non-SHA1 boot_aggregate digests to avoid ambiguity. + */ + if (alg_id != TPM_ALG_SHA1) { + for (i = TPM_PCR8; i < TPM_PCR10; i++) { + ima_pcrread(i, &d); + rc = crypto_shash_update(shash, d.digest, + crypto_shash_digestsize(tfm)); + } + } if (!rc) crypto_shash_final(shash, digest); return rc; |