diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-24 13:50:39 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-24 13:50:39 -0700 |
commit | 0350785b0a092c99c5ddd2ace0260dbe7b3f919f (patch) | |
tree | 3b9189b609f05d097f3ea9cb42c1a523308d53cb /security/integrity | |
parent | 7cf6a8a17f5b134b7e783c2d45c53298faef82a7 (diff) | |
parent | 048ae41bb0806cde340f4e5d5030398037ab0be8 (diff) |
Merge tag 'integrity-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull IMA updates from Mimi Zohar:
"New is IMA support for including fs-verity file digests and signatures
in the IMA measurement list as well as verifying the fs-verity file
digest based signatures, both based on policy.
In addition, are two bug fixes:
- avoid reading UEFI variables, which cause a page fault, on Apple
Macs with T2 chips.
- remove the original "ima" template Kconfig option to address a boot
command line ordering issue.
The rest is a mixture of code/documentation cleanup"
* tag 'integrity-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
integrity: Fix sparse warnings in keyring_handler
evm: Clean up some variables
evm: Return INTEGRITY_PASS for enum integrity_status value '0'
efi: Do not import certificates from UEFI Secure Boot for T2 Macs
fsverity: update the documentation
ima: support fs-verity file digest based version 3 signatures
ima: permit fsverity's file digests in the IMA measurement list
ima: define a new template field named 'd-ngv2' and templates
fs-verity: define a function to return the integrity protected file digest
ima: use IMA default hash algorithm for integrity violations
ima: fix 'd-ng' comments and documentation
ima: remove the IMA_TEMPLATE Kconfig option
ima: remove redundant initialization of pointer 'file'.
Diffstat (limited to 'security/integrity')
-rw-r--r-- | security/integrity/digsig.c | 3 | ||||
-rw-r--r-- | security/integrity/evm/evm.h | 3 | ||||
-rw-r--r-- | security/integrity/evm/evm_crypto.c | 2 | ||||
-rw-r--r-- | security/integrity/evm/evm_main.c | 2 | ||||
-rw-r--r-- | security/integrity/ima/Kconfig | 14 | ||||
-rw-r--r-- | security/integrity/ima/ima_api.c | 47 | ||||
-rw-r--r-- | security/integrity/ima/ima_appraise.c | 114 | ||||
-rw-r--r-- | security/integrity/ima/ima_main.c | 4 | ||||
-rw-r--r-- | security/integrity/ima/ima_policy.c | 82 | ||||
-rw-r--r-- | security/integrity/ima/ima_template.c | 4 | ||||
-rw-r--r-- | security/integrity/ima/ima_template_lib.c | 94 | ||||
-rw-r--r-- | security/integrity/ima/ima_template_lib.h | 4 | ||||
-rw-r--r-- | security/integrity/integrity.h | 27 | ||||
-rw-r--r-- | security/integrity/platform_certs/keyring_handler.c | 6 | ||||
-rw-r--r-- | security/integrity/platform_certs/keyring_handler.h | 8 | ||||
-rw-r--r-- | security/integrity/platform_certs/load_uefi.c | 33 |
16 files changed, 395 insertions, 52 deletions
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index c8c8a4a4e7a0..8a82a6c7f48a 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -75,7 +75,8 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, /* v1 API expect signature without xattr type */ return digsig_verify(keyring, sig + 1, siglen - 1, digest, digestlen); - case 2: + case 2: /* regular file data hash based signature */ + case 3: /* struct ima_file_id data based signature */ return asymmetric_verify(keyring, sig, siglen, digest, digestlen); } diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h index 0d44f41d16f8..f8b8c5004fc7 100644 --- a/security/integrity/evm/evm.h +++ b/security/integrity/evm/evm.h @@ -38,9 +38,6 @@ extern int evm_initialized; extern int evm_hmac_attrs; -extern struct crypto_shash *hmac_tfm; -extern struct crypto_shash *hash_tfm; - /* List of EVM protected security xattrs */ extern struct list_head evm_config_xattrnames; diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index 0450d79afdc8..a733aff02006 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -26,7 +26,7 @@ static unsigned char evmkey[MAX_KEY_SIZE]; static const int evmkey_len = MAX_KEY_SIZE; -struct crypto_shash *hmac_tfm; +static struct crypto_shash *hmac_tfm; static struct crypto_shash *evm_tfm[HASH_ALGO__LAST]; static DEFINE_MUTEX(mutex); diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 7d87772f0ce6..cc88f02c7562 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -436,7 +436,7 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) struct inode *inode = d_backing_inode(dentry); if (!evm_key_loaded() || !S_ISREG(inode->i_mode) || evm_fixmode) - return 0; + return INTEGRITY_PASS; return evm_verify_hmac(dentry, NULL, NULL, 0, NULL); } diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index f3a9cc201c8c..7249f16257c7 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -69,10 +69,9 @@ choice hash, defined as 20 bytes, and a null terminated pathname, limited to 255 characters. The 'ima-ng' measurement list template permits both larger hash digests and longer - pathnames. + pathnames. The configured default template can be replaced + by specifying "ima_template=" on the boot command line. - config IMA_TEMPLATE - bool "ima" config IMA_NG_TEMPLATE bool "ima-ng (default)" config IMA_SIG_TEMPLATE @@ -82,7 +81,6 @@ endchoice config IMA_DEFAULT_TEMPLATE string depends on IMA - default "ima" if IMA_TEMPLATE default "ima-ng" if IMA_NG_TEMPLATE default "ima-sig" if IMA_SIG_TEMPLATE @@ -102,19 +100,19 @@ choice config IMA_DEFAULT_HASH_SHA256 bool "SHA256" - depends on CRYPTO_SHA256=y && !IMA_TEMPLATE + depends on CRYPTO_SHA256=y config IMA_DEFAULT_HASH_SHA512 bool "SHA512" - depends on CRYPTO_SHA512=y && !IMA_TEMPLATE + depends on CRYPTO_SHA512=y config IMA_DEFAULT_HASH_WP512 bool "WP512" - depends on CRYPTO_WP512=y && !IMA_TEMPLATE + depends on CRYPTO_WP512=y config IMA_DEFAULT_HASH_SM3 bool "SM3" - depends on CRYPTO_SM3=y && !IMA_TEMPLATE + depends on CRYPTO_SM3=y endchoice config IMA_DEFAULT_HASH diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index c6805af46211..c1e76282b5ee 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -14,6 +14,7 @@ #include <linux/xattr.h> #include <linux/evm.h> #include <linux/iversion.h> +#include <linux/fsverity.h> #include "ima.h" @@ -200,6 +201,32 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode, allowed_algos); } +static int ima_get_verity_digest(struct integrity_iint_cache *iint, + struct ima_max_digest_data *hash) +{ + enum hash_algo verity_alg; + int ret; + + /* + * On failure, 'measure' policy rules will result in a file data + * hash containing 0's. + */ + ret = fsverity_get_digest(iint->inode, hash->digest, &verity_alg); + if (ret) + return ret; + + /* + * Unlike in the case of actually calculating the file hash, in + * the fsverity case regardless of the hash algorithm, return + * the verity digest to be included in the measurement list. A + * mismatch between the verity algorithm and the xattr signature + * algorithm, if one exists, will be detected later. + */ + hash->hdr.algo = verity_alg; + hash->hdr.length = hash_digest_size[verity_alg]; + return 0; +} + /* * ima_collect_measurement - collect file measurement * @@ -242,16 +269,30 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, */ i_version = inode_query_iversion(inode); hash.hdr.algo = algo; + hash.hdr.length = hash_digest_size[algo]; /* Initialize hash digest to 0's in case of failure */ memset(&hash.digest, 0, sizeof(hash.digest)); - if (buf) + if (iint->flags & IMA_VERITY_REQUIRED) { + result = ima_get_verity_digest(iint, &hash); + switch (result) { + case 0: + break; + case -ENODATA: + audit_cause = "no-verity-digest"; + break; + default: + audit_cause = "invalid-verity-digest"; + break; + } + } else if (buf) { result = ima_calc_buffer_hash(buf, size, &hash.hdr); - else + } else { result = ima_calc_file_hash(file, &hash.hdr); + } - if (result && result != -EBADF && result != -EINVAL) + if (result == -ENOMEM) goto out; length = sizeof(hash.hdr) + hash.hdr.length; diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 17232bbfb9f9..cdb84dccd24e 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -13,7 +13,9 @@ #include <linux/magic.h> #include <linux/ima.h> #include <linux/evm.h> +#include <linux/fsverity.h> #include <keys/system_keyring.h> +#include <uapi/linux/fsverity.h> #include "ima.h" @@ -183,13 +185,18 @@ enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, return ima_hash_algo; switch (xattr_value->type) { + case IMA_VERITY_DIGSIG: + sig = (typeof(sig))xattr_value; + if (sig->version != 3 || xattr_len <= sizeof(*sig) || + sig->hash_algo >= HASH_ALGO__LAST) + return ima_hash_algo; + return sig->hash_algo; case EVM_IMA_XATTR_DIGSIG: sig = (typeof(sig))xattr_value; if (sig->version != 2 || xattr_len <= sizeof(*sig) || sig->hash_algo >= HASH_ALGO__LAST) return ima_hash_algo; return sig->hash_algo; - break; case IMA_XATTR_DIGEST_NG: /* first byte contains algorithm id */ ret = xattr_value->data[0]; @@ -226,6 +233,40 @@ int ima_read_xattr(struct dentry *dentry, } /* + * calc_file_id_hash - calculate the hash of the ima_file_id struct data + * @type: xattr type [enum evm_ima_xattr_type] + * @algo: hash algorithm [enum hash_algo] + * @digest: pointer to the digest to be hashed + * @hash: (out) pointer to the hash + * + * IMA signature version 3 disambiguates the data that is signed by + * indirectly signing the hash of the ima_file_id structure data. + * + * Signing the ima_file_id struct is currently only supported for + * IMA_VERITY_DIGSIG type xattrs. + * + * Return 0 on success, error code otherwise. + */ +static int calc_file_id_hash(enum evm_ima_xattr_type type, + enum hash_algo algo, const u8 *digest, + struct ima_digest_data *hash) +{ + struct ima_file_id file_id = { + .hash_type = IMA_VERITY_DIGSIG, .hash_algorithm = algo}; + unsigned int unused = HASH_MAX_DIGESTSIZE - hash_digest_size[algo]; + + if (type != IMA_VERITY_DIGSIG) + return -EINVAL; + + memcpy(file_id.hash, digest, hash_digest_size[algo]); + + hash->algo = algo; + hash->length = hash_digest_size[algo]; + + return ima_calc_buffer_hash(&file_id, sizeof(file_id) - unused, hash); +} + +/* * xattr_verify - verify xattr digest or signature * * Verify whether the hash or signature matches the file contents. @@ -236,7 +277,10 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, struct evm_ima_xattr_data *xattr_value, int xattr_len, enum integrity_status *status, const char **cause) { + struct ima_max_digest_data hash; + struct signature_v2_hdr *sig; int rc = -EINVAL, hash_start = 0; + int mask; switch (xattr_value->type) { case IMA_XATTR_DIGEST_NG: @@ -246,7 +290,10 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, case IMA_XATTR_DIGEST: if (*status != INTEGRITY_PASS_IMMUTABLE) { if (iint->flags & IMA_DIGSIG_REQUIRED) { - *cause = "IMA-signature-required"; + if (iint->flags & IMA_VERITY_REQUIRED) + *cause = "verity-signature-required"; + else + *cause = "IMA-signature-required"; *status = INTEGRITY_FAIL; break; } @@ -274,6 +321,20 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, break; case EVM_IMA_XATTR_DIGSIG: set_bit(IMA_DIGSIG, &iint->atomic_flags); + + mask = IMA_DIGSIG_REQUIRED | IMA_VERITY_REQUIRED; + if ((iint->flags & mask) == mask) { + *cause = "verity-signature-required"; + *status = INTEGRITY_FAIL; + break; + } + + sig = (typeof(sig))xattr_value; + if (sig->version >= 3) { + *cause = "invalid-signature-version"; + *status = INTEGRITY_FAIL; + break; + } rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, (const char *)xattr_value, xattr_len, @@ -297,6 +358,44 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, *status = INTEGRITY_PASS; } break; + case IMA_VERITY_DIGSIG: + set_bit(IMA_DIGSIG, &iint->atomic_flags); + + if (iint->flags & IMA_DIGSIG_REQUIRED) { + if (!(iint->flags & IMA_VERITY_REQUIRED)) { + *cause = "IMA-signature-required"; + *status = INTEGRITY_FAIL; + break; + } + } + + sig = (typeof(sig))xattr_value; + if (sig->version != 3) { + *cause = "invalid-signature-version"; + *status = INTEGRITY_FAIL; + break; + } + + rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo, + iint->ima_hash->digest, &hash.hdr); + if (rc) { + *cause = "sigv3-hashing-error"; + *status = INTEGRITY_FAIL; + break; + } + + rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, + (const char *)xattr_value, + xattr_len, hash.digest, + hash.hdr.length); + if (rc) { + *cause = "invalid-verity-signature"; + *status = INTEGRITY_FAIL; + } else { + *status = INTEGRITY_PASS; + } + + break; default: *status = INTEGRITY_UNKNOWN; *cause = "unknown-ima-data"; @@ -396,8 +495,15 @@ int ima_appraise_measurement(enum ima_hooks func, if (rc && rc != -ENODATA) goto out; - cause = iint->flags & IMA_DIGSIG_REQUIRED ? - "IMA-signature-required" : "missing-hash"; + if (iint->flags & IMA_DIGSIG_REQUIRED) { + if (iint->flags & IMA_VERITY_REQUIRED) + cause = "verity-signature-required"; + else + cause = "IMA-signature-required"; + } else { + cause = "missing-hash"; + } + status = INTEGRITY_NOLABEL; if (file->f_mode & FMODE_CREATED) iint->flags |= IMA_NEW_FILE; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 3d3f8c5c502b..040b03ddc1c7 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -335,7 +335,7 @@ static int process_measurement(struct file *file, const struct cred *cred, hash_algo = ima_get_hash_algo(xattr_value, xattr_len); rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig); - if (rc != 0 && rc != -EBADF && rc != -EINVAL) + if (rc == -ENOMEM) goto out_locked; if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ @@ -432,7 +432,7 @@ int ima_file_mmap(struct file *file, unsigned long prot) int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) { struct ima_template_desc *template = NULL; - struct file *file = vma->vm_file; + struct file *file; char filename[NAME_MAX]; char *pathbuf = NULL; const char *pathname = NULL; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index eea6e92500b8..73917413365b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1023,6 +1023,7 @@ enum policy_opt { Opt_fowner_gt, Opt_fgroup_gt, Opt_uid_lt, Opt_euid_lt, Opt_gid_lt, Opt_egid_lt, Opt_fowner_lt, Opt_fgroup_lt, + Opt_digest_type, Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos, Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, Opt_label, Opt_err @@ -1065,6 +1066,7 @@ static const match_table_t policy_tokens = { {Opt_egid_lt, "egid<%s"}, {Opt_fowner_lt, "fowner<%s"}, {Opt_fgroup_lt, "fgroup<%s"}, + {Opt_digest_type, "digest_type=%s"}, {Opt_appraise_type, "appraise_type=%s"}, {Opt_appraise_flag, "appraise_flag=%s"}, {Opt_appraise_algos, "appraise_algos=%s"}, @@ -1172,6 +1174,21 @@ static void check_template_modsig(const struct ima_template_desc *template) #undef MSG } +/* + * Warn if the template does not contain the given field. + */ +static void check_template_field(const struct ima_template_desc *template, + const char *field, const char *msg) +{ + int i; + + for (i = 0; i < template->num_fields; i++) + if (!strcmp(template->fields[i]->field_id, field)) + return; + + pr_notice_once("%s", msg); +} + static bool ima_validate_rule(struct ima_rule_entry *entry) { /* Ensure that the action is set and is compatible with the flags */ @@ -1214,7 +1231,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) IMA_INMASK | IMA_EUID | IMA_PCR | IMA_FSNAME | IMA_GID | IMA_EGID | IMA_FGROUP | IMA_DIGSIG_REQUIRED | - IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS)) + IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | + IMA_VERITY_REQUIRED)) return false; break; @@ -1292,6 +1310,18 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) !(entry->flags & IMA_MODSIG_ALLOWED)) return false; + /* + * Unlike for regular IMA 'appraise' policy rules where security.ima + * xattr may contain either a file hash or signature, the security.ima + * xattr for fsverity must contain a file signature (sigv3). Ensure + * that 'appraise' rules for fsverity require file signatures by + * checking the IMA_DIGSIG_REQUIRED flag is set. + */ + if (entry->action == APPRAISE && + (entry->flags & IMA_VERITY_REQUIRED) && + !(entry->flags & IMA_DIGSIG_REQUIRED)) + return false; + return true; } @@ -1707,16 +1737,39 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) LSM_SUBJ_TYPE, AUDIT_SUBJ_TYPE); break; + case Opt_digest_type: + ima_log_string(ab, "digest_type", args[0].from); + if (entry->flags & IMA_DIGSIG_REQUIRED) + result = -EINVAL; + else if ((strcmp(args[0].from, "verity")) == 0) + entry->flags |= IMA_VERITY_REQUIRED; + else + result = -EINVAL; + break; case Opt_appraise_type: ima_log_string(ab, "appraise_type", args[0].from); - if ((strcmp(args[0].from, "imasig")) == 0) - entry->flags |= IMA_DIGSIG_REQUIRED; - else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && - strcmp(args[0].from, "imasig|modsig") == 0) - entry->flags |= IMA_DIGSIG_REQUIRED | + + if ((strcmp(args[0].from, "imasig")) == 0) { + if (entry->flags & IMA_VERITY_REQUIRED) + result = -EINVAL; + else + entry->flags |= IMA_DIGSIG_REQUIRED; + } else if (strcmp(args[0].from, "sigv3") == 0) { + /* Only fsverity supports sigv3 for now */ + if (entry->flags & IMA_VERITY_REQUIRED) + entry->flags |= IMA_DIGSIG_REQUIRED; + else + result = -EINVAL; + } else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && + strcmp(args[0].from, "imasig|modsig") == 0) { + if (entry->flags & IMA_VERITY_REQUIRED) + result = -EINVAL; + else + entry->flags |= IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED; - else + } else { result = -EINVAL; + } break; case Opt_appraise_flag: ima_log_string(ab, "appraise_flag", args[0].from); @@ -1797,6 +1850,15 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) check_template_modsig(template_desc); } + /* d-ngv2 template field recommended for unsigned fs-verity digests */ + if (!result && entry->action == MEASURE && + entry->flags & IMA_VERITY_REQUIRED) { + template_desc = entry->template ? entry->template : + ima_template_desc_current(); + check_template_field(template_desc, "d-ngv2", + "verity rules should include d-ngv2"); + } + audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; @@ -2149,11 +2211,15 @@ int ima_policy_show(struct seq_file *m, void *v) if (entry->template) seq_printf(m, "template=%s ", entry->template->name); if (entry->flags & IMA_DIGSIG_REQUIRED) { - if (entry->flags & IMA_MODSIG_ALLOWED) + if (entry->flags & IMA_VERITY_REQUIRED) + seq_puts(m, "appraise_type=sigv3 "); + else if (entry->flags & IMA_MODSIG_ALLOWED) seq_puts(m, "appraise_type=imasig|modsig "); else seq_puts(m, "appraise_type=imasig "); } + if (entry->flags & IMA_VERITY_REQUIRED) + seq_puts(m, "digest_type=verity "); if (entry->flags & IMA_CHECK_BLACKLIST) seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index db1ad6d7a57f..c25079faa208 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -20,6 +20,8 @@ static struct ima_template_desc builtin_templates[] = { {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT}, {.name = "ima-ng", .fmt = "d-ng|n-ng"}, {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"}, + {.name = "ima-ngv2", .fmt = "d-ngv2|n-ng"}, + {.name = "ima-sigv2", .fmt = "d-ngv2|n-ng|sig"}, {.name = "ima-buf", .fmt = "d-ng|n-ng|buf"}, {.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"}, {.name = "evm-sig", @@ -38,6 +40,8 @@ static const struct ima_template_field supported_fields[] = { .field_show = ima_show_template_string}, {.field_id = "d-ng", .field_init = ima_eventdigest_ng_init, .field_show = ima_show_template_digest_ng}, + {.field_id = "d-ngv2", .field_init = ima_eventdigest_ngv2_init, + .field_show = ima_show_template_digest_ngv2}, {.field_id = "n-ng", .field_init = ima_eventname_ng_init, .field_show = ima_show_template_string}, {.field_id = "sig", .field_init = ima_eventsig_init, diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 7155d17a3b75..c877f01a5471 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -24,11 +24,24 @@ static bool ima_template_hash_algo_allowed(u8 algo) enum data_formats { DATA_FMT_DIGEST = 0, DATA_FMT_DIGEST_WITH_ALGO, + DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, DATA_FMT_STRING, DATA_FMT_HEX, DATA_FMT_UINT }; +enum digest_type { + DIGEST_TYPE_IMA, + DIGEST_TYPE_VERITY, + DIGEST_TYPE__LAST +}; + +#define DIGEST_TYPE_NAME_LEN_MAX 7 /* including NUL */ +static const char * const digest_type_name[DIGEST_TYPE__LAST] = { + [DIGEST_TYPE_IMA] = "ima", + [DIGEST_TYPE_VERITY] = "verity" +}; + static int ima_write_template_field_data(const void *data, const u32 datalen, enum data_formats datafmt, struct ima_field_data *field_data) @@ -72,8 +85,9 @@ static void ima_show_template_data_ascii(struct seq_file *m, u32 buflen = field_data->len; switch (datafmt) { + case DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: case DATA_FMT_DIGEST_WITH_ALGO: - buf_ptr = strnchr(field_data->data, buflen, ':'); + buf_ptr = strrchr(field_data->data, ':'); if (buf_ptr != field_data->data) seq_printf(m, "%s", field_data->data); @@ -178,6 +192,14 @@ void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show, field_data); } +void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, + DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, + field_data); +} + void ima_show_template_string(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { @@ -265,26 +287,35 @@ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp, } static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize, - u8 hash_algo, + u8 digest_type, u8 hash_algo, struct ima_field_data *field_data) { /* * digest formats: * - DATA_FMT_DIGEST: digest - * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest, - * where <hash algo> is provided if the hash algorithm is not - * SHA1 or MD5 + * - DATA_FMT_DIGEST_WITH_ALGO: <hash algo> + ':' + '\0' + digest, + * - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: + * <digest type> + ':' + <hash algo> + ':' + '\0' + digest, + * + * where 'DATA_FMT_DIGEST' is the original digest format ('d') + * with a hash size limitation of 20 bytes, + * where <digest type> is either "ima" or "verity", + * where <hash algo> is the hash_algo_name[] string. */ - u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 }; + u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 + + IMA_MAX_DIGEST_SIZE] = { 0 }; enum data_formats fmt = DATA_FMT_DIGEST; u32 offset = 0; - if (hash_algo < HASH_ALGO__LAST) { + if (digest_type < DIGEST_TYPE__LAST && hash_algo < HASH_ALGO__LAST) { + fmt = DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO; + offset += 1 + sprintf(buffer, "%s:%s:", + digest_type_name[digest_type], + hash_algo_name[hash_algo]); + } else if (hash_algo < HASH_ALGO__LAST) { fmt = DATA_FMT_DIGEST_WITH_ALGO; - offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1, "%s", - hash_algo_name[hash_algo]); - buffer[offset] = ':'; - offset += 2; + offset += 1 + sprintf(buffer, "%s:", + hash_algo_name[hash_algo]); } if (digest) @@ -359,7 +390,8 @@ int ima_eventdigest_init(struct ima_event_data *event_data, cur_digestsize = hash.hdr.length; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, - HASH_ALGO__LAST, field_data); + DIGEST_TYPE__LAST, HASH_ALGO__LAST, + field_data); } /* @@ -368,8 +400,32 @@ out: int ima_eventdigest_ng_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { - u8 *cur_digest = NULL, hash_algo = HASH_ALGO_SHA1; + u8 *cur_digest = NULL, hash_algo = ima_hash_algo; + u32 cur_digestsize = 0; + + if (event_data->violation) /* recording a violation. */ + goto out; + + cur_digest = event_data->iint->ima_hash->digest; + cur_digestsize = event_data->iint->ima_hash->length; + + hash_algo = event_data->iint->ima_hash->algo; +out: + return ima_eventdigest_init_common(cur_digest, cur_digestsize, + DIGEST_TYPE__LAST, hash_algo, + field_data); +} + +/* + * This function writes the digest of an event (without size limit), + * prefixed with both the digest type and hash algorithm. + */ +int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + u8 *cur_digest = NULL, hash_algo = ima_hash_algo; u32 cur_digestsize = 0; + u8 digest_type = DIGEST_TYPE_IMA; if (event_data->violation) /* recording a violation. */ goto out; @@ -378,9 +434,12 @@ int ima_eventdigest_ng_init(struct ima_event_data *event_data, cur_digestsize = event_data->iint->ima_hash->length; hash_algo = event_data->iint->ima_hash->algo; + if (event_data->iint->flags & IMA_VERITY_REQUIRED) + digest_type = DIGEST_TYPE_VERITY; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, - hash_algo, field_data); + digest_type, hash_algo, + field_data); } /* @@ -415,7 +474,8 @@ int ima_eventdigest_modsig_init(struct ima_event_data *event_data, } return ima_eventdigest_init_common(cur_digest, cur_digestsize, - hash_algo, field_data); + DIGEST_TYPE__LAST, hash_algo, + field_data); } static int ima_eventname_init_common(struct ima_event_data *event_data, @@ -475,7 +535,9 @@ int ima_eventsig_init(struct ima_event_data *event_data, { struct evm_ima_xattr_data *xattr_value = event_data->xattr_value; - if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG)) + if (!xattr_value || + (xattr_value->type != EVM_IMA_XATTR_DIGSIG && + xattr_value->type != IMA_VERITY_DIGSIG)) return ima_eventevmsig_init(event_data, field_data); return ima_write_template_field_data(xattr_value, event_data->xattr_len, diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h index c71f1de95753..9f7c335f304f 100644 --- a/security/integrity/ima/ima_template_lib.h +++ b/security/integrity/ima/ima_template_lib.h @@ -21,6 +21,8 @@ void ima_show_template_digest(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data); void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data); +void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); void ima_show_template_string(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data); void ima_show_template_sig(struct seq_file *m, enum ima_show_type show, @@ -38,6 +40,8 @@ int ima_eventname_init(struct ima_event_data *event_data, struct ima_field_data *field_data); int ima_eventdigest_ng_init(struct ima_event_data *event_data, struct ima_field_data *field_data); +int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); int ima_eventdigest_modsig_init(struct ima_event_data *event_data, struct ima_field_data *field_data); int ima_eventname_ng_init(struct ima_event_data *event_data, diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 3510e413ea17..7167a6e99bdc 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -40,6 +40,7 @@ #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 #define IMA_MODSIG_ALLOWED 0x20000000 #define IMA_CHECK_BLACKLIST 0x40000000 +#define IMA_VERITY_REQUIRED 0x80000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_HASH | IMA_APPRAISE_SUBMASK) @@ -78,6 +79,7 @@ enum evm_ima_xattr_type { EVM_IMA_XATTR_DIGSIG, IMA_XATTR_DIGEST_NG, EVM_XATTR_PORTABLE_DIGSIG, + IMA_VERITY_DIGSIG, IMA_XATTR_LAST }; @@ -92,7 +94,7 @@ struct evm_xattr { u8 digest[SHA1_DIGEST_SIZE]; } __packed; -#define IMA_MAX_DIGEST_SIZE 64 +#define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE struct ima_digest_data { u8 algo; @@ -121,7 +123,14 @@ struct ima_max_digest_data { } __packed; /* - * signature format v2 - for using with asymmetric keys + * signature header format v2 - for using with asymmetric keys + * + * The signature_v2_hdr struct includes a signature format version + * to simplify defining new signature formats. + * + * signature format: + * version 2: regular file data hash based signature + * version 3: struct ima_file_id data based signature */ struct signature_v2_hdr { uint8_t type; /* xattr type */ @@ -132,6 +141,20 @@ struct signature_v2_hdr { uint8_t sig[]; /* signature payload */ } __packed; +/* + * IMA signature version 3 disambiguates the data that is signed, by + * indirectly signing the hash of the ima_file_id structure data, + * containing either the fsverity_descriptor struct digest or, in the + * future, the regular IMA file hash. + * + * (The hash of the ima_file_id structure is only of the portion used.) + */ +struct ima_file_id { + __u8 hash_type; /* xattr type [enum evm_ima_xattr_type] */ + __u8 hash_algorithm; /* Digest algorithm [enum hash_algo] */ + __u8 hash[HASH_MAX_DIGESTSIZE]; +} __packed; + /* integrity data associated with an inode */ struct integrity_iint_cache { struct rb_node rb_node; /* rooted in integrity_iint_tree */ diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c index a2464f3e66cc..8a1124e4d769 100644 --- a/security/integrity/platform_certs/keyring_handler.c +++ b/security/integrity/platform_certs/keyring_handler.c @@ -51,7 +51,7 @@ __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type) { if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) return add_to_platform_keyring; - return 0; + return NULL; } /* @@ -66,7 +66,7 @@ __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type) else return add_to_platform_keyring; } - return 0; + return NULL; } /* @@ -81,5 +81,5 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) return uefi_blacklist_binary; if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) return uefi_revocation_list_x509; - return 0; + return NULL; } diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h index 284558f30411..212d894a8c0c 100644 --- a/security/integrity/platform_certs/keyring_handler.h +++ b/security/integrity/platform_certs/keyring_handler.h @@ -35,3 +35,11 @@ efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type); efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type); #endif + +#ifndef UEFI_QUIRK_SKIP_CERT +#define UEFI_QUIRK_SKIP_CERT(vendor, product) \ + .matches = { \ + DMI_MATCH(DMI_BOARD_VENDOR, vendor), \ + DMI_MATCH(DMI_PRODUCT_NAME, product), \ + }, +#endif diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index 5f45c3c07dbd..093894a640dc 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -3,6 +3,7 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/cred.h> +#include <linux/dmi.h> #include <linux/err.h> #include <linux/efi.h> #include <linux/slab.h> @@ -13,6 +14,31 @@ #include "keyring_handler.h" /* + * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot + * certificates causes occurrence of a page fault in Apple's firmware and + * a crash disabling EFI runtime services. The following quirk skips reading + * these variables. + */ +static const struct dmi_system_id uefi_skip_cert[] = { + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,3") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,4") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,3") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,4") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir9,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacMini8,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacPro7,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,2") }, + { } +}; + +/* * Look to see if a UEFI variable called MokIgnoreDB exists and return true if * it does. * @@ -138,6 +164,13 @@ static int __init load_uefi_certs(void) unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0; efi_status_t status; int rc = 0; + const struct dmi_system_id *dmi_id; + + dmi_id = dmi_first_match(uefi_skip_cert); + if (dmi_id) { + pr_err("Reading UEFI Secure Boot Certs is not supported on T2 Macs.\n"); + return false; + } if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) return false; |