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'.

Documentation/ABI/testing/ima_policy

···
 				[fowner=] [fgroup=]]
 			lsm:	[[subj_user=] [subj_role=] [subj_type=]
 				 [obj_user=] [obj_role=] [obj_type=]]
-			option:	[[appraise_type=]] [template=] [permit_directio]
-				[appraise_flag=] [appraise_algos=] [keyrings=]
+			option:	[digest_type=] [template=] [permit_directio]
+				[appraise_type=] [appraise_flag=]
+				[appraise_algos=] [keyrings=]
 		  base:
 			func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
 				[FIRMWARE_CHECK]
···
 			fgroup:= decimal value
 		  lsm:  are LSM specific
 		  option:
-			appraise_type:= [imasig] [imasig|modsig]
+			appraise_type:= [imasig] | [imasig|modsig] | [sigv3]
+			    where 'imasig' is the original or the signature
+				format v2.
+			    where 'modsig' is an appended signature,
+			    where 'sigv3' is the signature format v3. (Currently
+				limited to fsverity digest based signatures
+				stored in security.ima xattr. Requires
+				specifying "digest_type=verity" first.)
+
 			appraise_flag:= [check_blacklist]
 			Currently, blacklist check is only for files signed with appended
 			signature.
+			digest_type:= verity
+			    Require fs-verity's file digest instead of the
+			    regular IMA file hash.
 			keyrings:= list of keyrings
 			(eg, .builtin_trusted_keys|.ima). Only valid
 			when action is "measure" and func is KEY_CHECK.
···
 		security.ima xattr of a file:
 
 			appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512
+
+		Example of a 'measure' rule requiring fs-verity's digests
+		with indication of type of digest in the measurement list.
+
+			measure func=FILE_CHECK digest_type=verity \
+				template=ima-ngv2
+
+		Example of 'measure' and 'appraise' rules requiring fs-verity
+		signatures (format version 3) stored in security.ima xattr.
+
+		The 'measure' rule specifies the 'ima-sigv3' template option,
+		which includes the indication of type of digest and the file
+		signature in the measurement list.
+
+			measure func=BPRM_CHECK digest_type=verity \
+				template=ima-sigv3
+
+
+		The 'appraise' rule specifies the type and signature format
+		version (sigv3) required.
+
+			appraise func=BPRM_CHECK digest_type=verity \
+				appraise_type=sigv3
+
+		All of these policy rules could, for example, be constrained
+		either based on a filesystem's UUID (fsuuid) or based on LSM
+		labels.

Documentation/admin-guide/kernel-parameters.txt

···
 
 	ima_template=	[IMA]
 			Select one of defined IMA measurements template formats.
-			Formats: { "ima" | "ima-ng" | "ima-sig" }
+			Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
+				   "ima-sigv2" }
 			Default: "ima-ng"
 
 	ima_template_fmt=

Documentation/filesystems/fsverity.rst

···
 updated and potentially user-installed, so dm-verity cannot be used.
 
 The base fs-verity feature is a hashing mechanism only; actually
-authenticating the files is up to userspace.  However, to meet some
-users' needs, fs-verity optionally supports a simple signature
-verification mechanism where users can configure the kernel to require
-that all fs-verity files be signed by a key loaded into a keyring; see
-`Built-in signature verification`_.  Support for fs-verity file hashes
-in IMA (Integrity Measurement Architecture) policies is also planned.
+authenticating the files may be done by:
+
+* Userspace-only
+
+* Builtin signature verification + userspace policy
+
+  fs-verity optionally supports a simple signature verification
+  mechanism where users can configure the kernel to require that
+  all fs-verity files be signed by a key loaded into a keyring;
+  see `Built-in signature verification`_.
+
+* Integrity Measurement Architecture (IMA)
+
+  IMA supports including fs-verity file digests and signatures in the
+  IMA measurement list and verifying fs-verity based file signatures
+  stored as security.ima xattrs, based on policy.
+
 
 User API
 ========
···
     hashed and what to do with those hashes, such as log them,
     authenticate them, or add them to a measurement list.
 
-    IMA is planned to support the fs-verity hashing mechanism as an
-    alternative to doing full file hashes, for people who want the
-    performance and security benefits of the Merkle tree based hash.
-    But it doesn't make sense to force all uses of fs-verity to be
-    through IMA.  As a standalone filesystem feature, fs-verity
-    already meets many users' needs, and it's testable like other
+    IMA supports the fs-verity hashing mechanism as an alternative
+    to full file hashes, for those who want the performance and
+    security benefits of the Merkle tree based hash.  However, it
+    doesn't make sense to force all uses of fs-verity to be through
+    IMA.  fs-verity already meets many users' needs even as a
+    standalone filesystem feature, and it's testable like other
     filesystem features e.g. with xfstests.
 
 :Q: Isn't fs-verity useless because the attacker can just modify the

Documentation/security/IMA-templates.rst

···
    calculated with the SHA1 or MD5 hash algorithm;
  - 'n': the name of the event (i.e. the file name), with size up to 255 bytes;
  - 'd-ng': the digest of the event, calculated with an arbitrary hash
-   algorithm (field format: [<hash algo>:]digest, where the digest
-   prefix is shown only if the hash algorithm is not SHA1 or MD5);
+   algorithm (field format: <hash algo>:digest);
+ - 'd-ngv2': same as d-ng, but prefixed with the "ima" or "verity" digest type
+   (field format: <digest type>:<hash algo>:digest);
  - 'd-modsig': the digest of the event without the appended modsig;
  - 'n-ng': the name of the event, without size limitations;
- - 'sig': the file signature, or the EVM portable signature if the file
-   signature is not found;
+ - 'sig': the file signature, based on either the file's/fsverity's digest[1],
+   or the EVM portable signature, if 'security.ima' contains a file hash.
  - 'modsig' the appended file signature;
  - 'buf': the buffer data that was used to generate the hash without size limitations;
  - 'evmsig': the EVM portable signature;
···
 
  - "ima": its format is ``d|n``;
  - "ima-ng" (default): its format is ``d-ng|n-ng``;
+ - "ima-ngv2": its format is ``d-ngv2|n-ng``;
  - "ima-sig": its format is ``d-ng|n-ng|sig``;
+ - "ima-sigv2": its format is ``d-ngv2|n-ng|sig``;
  - "ima-buf": its format is ``d-ng|n-ng|buf``;
  - "ima-modsig": its format is ``d-ng|n-ng|sig|d-modsig|modsig``;
  - "evm-sig": its format is ``d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode``;

fs/verity/Kconfig

···
 config FS_VERITY
 	bool "FS Verity (read-only file-based authenticity protection)"
 	select CRYPTO
+	select CRYPTO_HASH_INFO
 	# SHA-256 is implied as it's intended to be the default hash algorithm.
 	# To avoid bloat, other wanted algorithms must be selected explicitly.
 	# Note that CRYPTO_SHA256 denotes the generic C implementation, but

fs/verity/fsverity_private.h

···
 
 #define pr_fmt(fmt) "fs-verity: " fmt
 
-#include <crypto/sha2.h>
 #include <linux/fsverity.h>
 #include <linux/mempool.h>
 
···
  * it's enough for over U64_MAX bytes of data using SHA-256 and 4K blocks.
  */
 #define FS_VERITY_MAX_LEVELS		8
-
-/*
- * Largest digest size among all hash algorithms supported by fs-verity.
- * Currently assumed to be <= size of fsverity_descriptor::root_hash.
- */
-#define FS_VERITY_MAX_DIGEST_SIZE	SHA512_DIGEST_SIZE
 
 /* A hash algorithm supported by fs-verity */
 struct fsverity_hash_alg {

fs/verity/measure.c

···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(fsverity_ioctl_measure);
+
+/**
+ * fsverity_get_digest() - get a verity file's digest
+ * @inode: inode to get digest of
+ * @digest: (out) pointer to the digest
+ * @alg: (out) pointer to the hash algorithm enumeration
+ *
+ * Return the file hash algorithm and digest of an fsverity protected file.
+ * Assumption: before calling fsverity_get_digest(), the file must have been
+ * opened.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int fsverity_get_digest(struct inode *inode,
+			u8 digest[FS_VERITY_MAX_DIGEST_SIZE],
+			enum hash_algo *alg)
+{
+	const struct fsverity_info *vi;
+	const struct fsverity_hash_alg *hash_alg;
+	int i;
+
+	vi = fsverity_get_info(inode);
+	if (!vi)
+		return -ENODATA; /* not a verity file */
+
+	hash_alg = vi->tree_params.hash_alg;
+	memset(digest, 0, FS_VERITY_MAX_DIGEST_SIZE);
+
+	/* convert the verity hash algorithm name to a hash_algo_name enum */
+	i = match_string(hash_algo_name, HASH_ALGO__LAST, hash_alg->name);
+	if (i < 0)
+		return -EINVAL;
+	*alg = i;
+
+	if (WARN_ON_ONCE(hash_alg->digest_size != hash_digest_size[*alg]))
+		return -EINVAL;
+	memcpy(digest, vi->file_digest, hash_alg->digest_size);
+
+	pr_debug("file digest %s:%*phN\n", hash_algo_name[*alg],
+		 hash_digest_size[*alg], digest);
+
+	return 0;
+}

include/linux/fsverity.h

···
 #define _LINUX_FSVERITY_H
 
 #include <linux/fs.h>
+#include <crypto/hash_info.h>
+#include <crypto/sha2.h>
 #include <uapi/linux/fsverity.h>
+
+/*
+ * Largest digest size among all hash algorithms supported by fs-verity.
+ * Currently assumed to be <= size of fsverity_descriptor::root_hash.
+ */
+#define FS_VERITY_MAX_DIGEST_SIZE	SHA512_DIGEST_SIZE
 
 /* Verity operations for filesystems */
 struct fsverity_operations {
···
 /* measure.c */
 
 int fsverity_ioctl_measure(struct file *filp, void __user *arg);
+int fsverity_get_digest(struct inode *inode,
+			u8 digest[FS_VERITY_MAX_DIGEST_SIZE],
+			enum hash_algo *alg);
 
 /* open.c */
 
···
 /* measure.c */
 
 static inline int fsverity_ioctl_measure(struct file *filp, void __user *arg)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int fsverity_get_digest(struct inode *inode,
+				      u8 digest[FS_VERITY_MAX_DIGEST_SIZE],
+				      enum hash_algo *alg)
 {
 	return -EOPNOTSUPP;
 }

security/integrity/digsig.c

···
 		/* 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);
 	}

security/integrity/evm/evm.h

···
 
 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;
 

security/integrity/evm/evm_crypto.c

···
 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);

security/integrity/evm/evm_main.c

···
 	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);
 }
 

security/integrity/ima/Kconfig

···
 	  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
···
 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
 
···
 
 	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

security/integrity/ima/ima_api.c

···
 #include <linux/xattr.h>
 #include <linux/evm.h>
 #include <linux/iversion.h>
+#include <linux/fsverity.h>
 
 #include "ima.h"
 
···
 				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
  *
···
 	 */
 	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;

security/integrity/ima/ima_appraise.c

···
 #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"
 
···
 		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];
···
 }
 
 /*
+ * 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.
···
 			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:
···
 	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;
 			}
···
 		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,
···
 		} else {
 			*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;
···
 		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;

security/integrity/ima/ima_main.c

···
 	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 */
···
 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;

security/integrity/ima/ima_policy.c

···
 	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
···
 	{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"},
···
 #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 */
···
 				     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;
···
 	/* Ensure that combinations of flags are compatible with each other */
 	if (entry->flags & IMA_CHECK_BLACKLIST &&
 	    !(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;
···
 						   LSM_SUBJ_TYPE,
 						   AUDIT_SUBJ_TYPE);
 			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 |
-						IMA_MODSIG_ALLOWED;
+		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) {
+				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 {
+				result = -EINVAL;
+			}
 			break;
 		case Opt_appraise_flag:
 			ima_log_string(ab, "appraise_flag", args[0].from);
···
 		template_desc = entry->template ? entry->template :
 						  ima_template_desc_current();
 		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);
···
 	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)

security/integrity/ima/ima_template.c

···
 	{.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",
···
 	 .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,

security/integrity/ima/ima_template_lib.c

···
 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,
···
 	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);
 
···
 				     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)
 {
···
 }
 
 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)
···
 	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);
 }
 
 /*
···
 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. */
···
 	hash_algo = event_data->iint->ima_hash->algo;
 out:
 	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
-					   hash_algo, field_data);
+					   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;
+
+	cur_digest = event_data->iint->ima_hash->digest;
+	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,
+					   digest_type, hash_algo,
+					   field_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,
···
 {
 	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,

security/integrity/ima/ima_template_lib.h

···
 			      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,
···
 		       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,

security/integrity/integrity.h

···
 #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)
···
 	EVM_IMA_XATTR_DIGSIG,
 	IMA_XATTR_DIGEST_NG,
 	EVM_XATTR_PORTABLE_DIGSIG,
+	IMA_VERITY_DIGSIG,
 	IMA_XATTR_LAST
 };
 
···
 	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;
···
 } __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 */
···
 	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
 	__be16 sig_size;	/* signature size */
 	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 */

security/integrity/platform_certs/keyring_handler.c

···
 {
 	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
 		return add_to_platform_keyring;
-	return 0;
+	return NULL;
 }
 
 /*
···
 		else
 			return add_to_platform_keyring;
 	}
-	return 0;
+	return NULL;
 }
 
 /*
···
 		return uefi_blacklist_binary;
 	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
 		return uefi_revocation_list_x509;
-	return 0;
+	return NULL;
 }

security/integrity/platform_certs/keyring_handler.h

···
 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

security/integrity/platform_certs/load_uefi.c

···
 #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>
···
 #include <keys/system_keyring.h>
 #include "../integrity.h"
 #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
···
 	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;