diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index fc376a323908..29ebe9afdac4 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -37,7 +37,7 @@ Description:
 			euid:= decimal value
 			fowner:= decimal value
 		lsm:  	are LSM specific
-		option:	appraise_type:= [imasig]
+		option:	appraise_type:= [imasig] [imasig|modsig]
 			template:= name of a defined IMA template type
 			(eg, ima-ng). Only valid when action is "measure".
 			pcr:= decimal value
@@ -105,3 +105,7 @@ Description:
 
 			measure func=KEXEC_KERNEL_CHECK pcr=4
 			measure func=KEXEC_INITRAMFS_CHECK pcr=5
+
+		Example of appraise rule allowing modsig appended signatures:
+
+			appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
diff --git a/Documentation/security/IMA-templates.rst b/Documentation/security/IMA-templates.rst
index 3d1cca287aa4..c5a8432972ef 100644
--- a/Documentation/security/IMA-templates.rst
+++ b/Documentation/security/IMA-templates.rst
@@ -68,8 +68,10 @@ descriptors by adding their identifier to the format string
  - '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);
+ - '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;
+ - 'modsig' the appended file signature;
  - 'buf': the buffer data that was used to generate the hash without size limitations;
 
 
@@ -79,6 +81,7 @@ Below, there is the list of defined template descriptors:
  - "ima-ng" (default): its format is ``d-ng|n-ng``;
  - "ima-sig": its format is ``d-ng|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``;
 
 
 Use
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index f933a473b128..68f7c2b16ff7 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -556,7 +556,7 @@ config ARCH_HAS_KEXEC_PURGATORY
 
 config KEXEC_VERIFY_SIG
 	bool "Verify kernel signature during kexec_file_load() syscall"
-	depends on KEXEC_FILE && SYSTEM_DATA_VERIFICATION
+	depends on KEXEC_FILE && MODULE_SIG_FORMAT
 	help
 	  This option makes kernel signature verification mandatory for
 	  the kexec_file_load() syscall.
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index fbdd3ea73667..1ac9fbc6e01e 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -10,7 +10,7 @@
 #include <linux/elf.h>
 #include <linux/errno.h>
 #include <linux/kexec.h>
-#include <linux/module.h>
+#include <linux/module_signature.h>
 #include <linux/verification.h>
 #include <asm/boot_data.h>
 #include <asm/ipl.h>
@@ -23,28 +23,6 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
 };
 
 #ifdef CONFIG_KEXEC_VERIFY_SIG
-/*
- * Module signature information block.
- *
- * The constituents of the signature section are, in order:
- *
- *	- Signer's name
- *	- Key identifier
- *	- Signature data
- *	- Information block
- */
-struct module_signature {
-	u8	algo;		/* Public-key crypto algorithm [0] */
-	u8	hash;		/* Digest algorithm [0] */
-	u8	id_type;	/* Key identifier type [PKEY_ID_PKCS7] */
-	u8	signer_len;	/* Length of signer's name [0] */
-	u8	key_id_len;	/* Length of key identifier [0] */
-	u8	__pad[3];
-	__be32	sig_len;	/* Length of signature data */
-};
-
-#define PKEY_ID_PKCS7 2
-
 int s390_verify_sig(const char *kernel, unsigned long kernel_len)
 {
 	const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 1eba08a1af82..798291177186 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -190,33 +190,27 @@ late_initcall(load_system_certificate_list);
 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
 
 /**
- * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
+ * verify_pkcs7_message_sig - Verify a PKCS#7-based signature on system data.
  * @data: The data to be verified (NULL if expecting internal data).
  * @len: Size of @data.
- * @raw_pkcs7: The PKCS#7 message that is the signature.
- * @pkcs7_len: The size of @raw_pkcs7.
+ * @pkcs7: The PKCS#7 message that is the signature.
  * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
  *					(void *)1UL for all trusted keys).
  * @usage: The use to which the key is being put.
  * @view_content: Callback to gain access to content.
  * @ctx: Context for callback.
  */
-int verify_pkcs7_signature(const void *data, size_t len,
-			   const void *raw_pkcs7, size_t pkcs7_len,
-			   struct key *trusted_keys,
-			   enum key_being_used_for usage,
-			   int (*view_content)(void *ctx,
-					       const void *data, size_t len,
-					       size_t asn1hdrlen),
-			   void *ctx)
+int verify_pkcs7_message_sig(const void *data, size_t len,
+			     struct pkcs7_message *pkcs7,
+			     struct key *trusted_keys,
+			     enum key_being_used_for usage,
+			     int (*view_content)(void *ctx,
+						 const void *data, size_t len,
+						 size_t asn1hdrlen),
+			     void *ctx)
 {
-	struct pkcs7_message *pkcs7;
 	int ret;
 
-	pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
-	if (IS_ERR(pkcs7))
-		return PTR_ERR(pkcs7);
-
 	/* The data should be detached - so we need to supply it. */
 	if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
 		pr_err("PKCS#7 signature with non-detached data\n");
@@ -269,6 +263,41 @@ int verify_pkcs7_signature(const void *data, size_t len,
 	}
 
 error:
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+
+/**
+ * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
+ * @data: The data to be verified (NULL if expecting internal data).
+ * @len: Size of @data.
+ * @raw_pkcs7: The PKCS#7 message that is the signature.
+ * @pkcs7_len: The size of @raw_pkcs7.
+ * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
+ *					(void *)1UL for all trusted keys).
+ * @usage: The use to which the key is being put.
+ * @view_content: Callback to gain access to content.
+ * @ctx: Context for callback.
+ */
+int verify_pkcs7_signature(const void *data, size_t len,
+			   const void *raw_pkcs7, size_t pkcs7_len,
+			   struct key *trusted_keys,
+			   enum key_being_used_for usage,
+			   int (*view_content)(void *ctx,
+					       const void *data, size_t len,
+					       size_t asn1hdrlen),
+			   void *ctx)
+{
+	struct pkcs7_message *pkcs7;
+	int ret;
+
+	pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
+	if (IS_ERR(pkcs7))
+		return PTR_ERR(pkcs7);
+
+	ret = verify_pkcs7_message_sig(data, len, pkcs7, trusted_keys, usage,
+				       view_content, ctx);
+
 	pkcs7_free_message(pkcs7);
 	pr_devel("<==%s() = %d\n", __func__, ret);
 	return ret;
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 11bee67fa9cc..ce49820caa97 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -12,6 +12,7 @@
 #include <linux/err.h>
 #include <linux/asn1.h>
 #include <crypto/hash.h>
+#include <crypto/hash_info.h>
 #include <crypto/public_key.h>
 #include "pkcs7_parser.h"
 
@@ -29,6 +30,10 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
 
 	kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo);
 
+	/* The digest was calculated already. */
+	if (sig->digest)
+		return 0;
+
 	if (!sinfo->sig->hash_algo)
 		return -ENOPKG;
 
@@ -117,6 +122,34 @@ error_no_desc:
 	return ret;
 }
 
+int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u32 *len,
+		     enum hash_algo *hash_algo)
+{
+	struct pkcs7_signed_info *sinfo = pkcs7->signed_infos;
+	int i, ret;
+
+	/*
+	 * This function doesn't support messages with more than one signature.
+	 */
+	if (sinfo == NULL || sinfo->next != NULL)
+		return -EBADMSG;
+
+	ret = pkcs7_digest(pkcs7, sinfo);
+	if (ret)
+		return ret;
+
+	*buf = sinfo->sig->digest;
+	*len = sinfo->sig->digest_size;
+
+	for (i = 0; i < HASH_ALGO__LAST; i++)
+		if (!strcmp(hash_algo_name[i], sinfo->sig->hash_algo)) {
+			*hash_algo = i;
+			break;
+		}
+
+	return 0;
+}
+
 /*
  * Find the key (X.509 certificate) to use to verify a PKCS#7 message.  PKCS#7
  * uses the issuer's name and the issuing certificate serial number for
diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h
index 96071bee03ac..38ec7f5f9041 100644
--- a/include/crypto/pkcs7.h
+++ b/include/crypto/pkcs7.h
@@ -9,6 +9,7 @@
 #define _CRYPTO_PKCS7_H
 
 #include <linux/verification.h>
+#include <linux/hash_info.h>
 #include <crypto/public_key.h>
 
 struct key;
@@ -40,4 +41,7 @@ extern int pkcs7_verify(struct pkcs7_message *pkcs7,
 extern int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7,
 				      const void *data, size_t datalen);
 
+extern int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf,
+			    u32 *len, enum hash_algo *hash_algo);
+
 #endif /* _CRYPTO_PKCS7_H */
diff --git a/include/linux/module.h b/include/linux/module.h
index b1a67352d2dc..6d20895e7739 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -26,9 +26,6 @@
 #include <linux/percpu.h>
 #include <asm/module.h>
 
-/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
-#define MODULE_SIG_STRING "~Module signature appended~\n"
-
 /* Not Yet Implemented */
 #define MODULE_SUPPORTED_DEVICE(name)
 
diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h
new file mode 100644
index 000000000000..7eb4b00381ac
--- /dev/null
+++ b/include/linux/module_signature.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Module signature handling.
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _LINUX_MODULE_SIGNATURE_H
+#define _LINUX_MODULE_SIGNATURE_H
+
+#include <linux/types.h>
+
+/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
+#define MODULE_SIG_STRING "~Module signature appended~\n"
+
+enum pkey_id_type {
+	PKEY_ID_PGP,		/* OpenPGP generated key ID */
+	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
+	PKEY_ID_PKCS7,		/* Signature in PKCS#7 message */
+};
+
+/*
+ * Module signature information block.
+ *
+ * The constituents of the signature section are, in order:
+ *
+ *	- Signer's name
+ *	- Key identifier
+ *	- Signature data
+ *	- Information block
+ */
+struct module_signature {
+	u8	algo;		/* Public-key crypto algorithm [0] */
+	u8	hash;		/* Digest algorithm [0] */
+	u8	id_type;	/* Key identifier type [PKEY_ID_PKCS7] */
+	u8	signer_len;	/* Length of signer's name [0] */
+	u8	key_id_len;	/* Length of key identifier [0] */
+	u8	__pad[3];
+	__be32	sig_len;	/* Length of signature data */
+};
+
+int mod_check_sig(const struct module_signature *ms, size_t file_len,
+		  const char *name);
+
+#endif /* _LINUX_MODULE_SIGNATURE_H */
diff --git a/include/linux/verification.h b/include/linux/verification.h
index 32d990d163c4..911ab7c2b1ab 100644
--- a/include/linux/verification.h
+++ b/include/linux/verification.h
@@ -32,6 +32,7 @@ extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
 
 struct key;
+struct pkcs7_message;
 
 extern int verify_pkcs7_signature(const void *data, size_t len,
 				  const void *raw_pkcs7, size_t pkcs7_len,
@@ -41,6 +42,15 @@ extern int verify_pkcs7_signature(const void *data, size_t len,
 						      const void *data, size_t len,
 						      size_t asn1hdrlen),
 				  void *ctx);
+extern int verify_pkcs7_message_sig(const void *data, size_t len,
+				    struct pkcs7_message *pkcs7,
+				    struct key *trusted_keys,
+				    enum key_being_used_for usage,
+				    int (*view_content)(void *ctx,
+							const void *data,
+							size_t len,
+							size_t asn1hdrlen),
+				    void *ctx);
 
 #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
 extern int verify_pefile_signature(const void *pebuf, unsigned pelen,
diff --git a/init/Kconfig b/init/Kconfig
index 57123594a7ca..92c867e25a29 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1963,6 +1963,10 @@ config BASE_SMALL
 	default 0 if BASE_FULL
 	default 1 if !BASE_FULL
 
+config MODULE_SIG_FORMAT
+	def_bool n
+	select SYSTEM_DATA_VERIFICATION
+
 menuconfig MODULES
 	bool "Enable loadable module support"
 	option modules
@@ -2047,7 +2051,7 @@ config MODULE_SRCVERSION_ALL
 
 config MODULE_SIG
 	bool "Module signature verification"
-	select SYSTEM_DATA_VERIFICATION
+	select MODULE_SIG_FORMAT
 	help
 	  Check modules for valid signatures upon load: the signature
 	  is simply appended to the module. For more information see
diff --git a/kernel/Makefile b/kernel/Makefile
index 25f9d83d1bbf..daad787fb795 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -58,6 +58,7 @@ endif
 obj-$(CONFIG_UID16) += uid16.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_MODULE_SIG) += module_signing.o
+obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_CRASH_CORE) += crash_core.o
diff --git a/kernel/module.c b/kernel/module.c
index 32873bcce738..edbe42755a27 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -7,6 +7,7 @@
 #include <linux/export.h>
 #include <linux/extable.h>
 #include <linux/moduleloader.h>
+#include <linux/module_signature.h>
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
diff --git a/kernel/module_signature.c b/kernel/module_signature.c
new file mode 100644
index 000000000000..4224a1086b7d
--- /dev/null
+++ b/kernel/module_signature.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Module signature checker
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/errno.h>
+#include <linux/printk.h>
+#include <linux/module_signature.h>
+#include <asm/byteorder.h>
+
+/**
+ * mod_check_sig - check that the given signature is sane
+ *
+ * @ms:		Signature to check.
+ * @file_len:	Size of the file to which @ms is appended.
+ * @name:	What is being checked. Used for error messages.
+ */
+int mod_check_sig(const struct module_signature *ms, size_t file_len,
+		  const char *name)
+{
+	if (be32_to_cpu(ms->sig_len) >= file_len - sizeof(*ms))
+		return -EBADMSG;
+
+	if (ms->id_type != PKEY_ID_PKCS7) {
+		pr_err("%s: Module is not signed with expected PKCS#7 message\n",
+		       name);
+		return -ENOPKG;
+	}
+
+	if (ms->algo != 0 ||
+	    ms->hash != 0 ||
+	    ms->signer_len != 0 ||
+	    ms->key_id_len != 0 ||
+	    ms->__pad[0] != 0 ||
+	    ms->__pad[1] != 0 ||
+	    ms->__pad[2] != 0) {
+		pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n",
+		       name);
+		return -EBADMSG;
+	}
+
+	return 0;
+}
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index b10fb1986ca9..9d9fc678c91d 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -7,37 +7,13 @@
 
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/module_signature.h>
 #include <linux/string.h>
 #include <linux/verification.h>
 #include <crypto/public_key.h>
 #include "module-internal.h"
 
-enum pkey_id_type {
-	PKEY_ID_PGP,		/* OpenPGP generated key ID */
-	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
-	PKEY_ID_PKCS7,		/* Signature in PKCS#7 message */
-};
-
-/*
- * Module signature information block.
- *
- * The constituents of the signature section are, in order:
- *
- *	- Signer's name
- *	- Key identifier
- *	- Signature data
- *	- Information block
- */
-struct module_signature {
-	u8	algo;		/* Public-key crypto algorithm [0] */
-	u8	hash;		/* Digest algorithm [0] */
-	u8	id_type;	/* Key identifier type [PKEY_ID_PKCS7] */
-	u8	signer_len;	/* Length of signer's name [0] */
-	u8	key_id_len;	/* Length of key identifier [0] */
-	u8	__pad[3];
-	__be32	sig_len;	/* Length of signature data */
-};
-
 /*
  * Verify the signature on a module.
  */
@@ -45,6 +21,7 @@ int mod_verify_sig(const void *mod, struct load_info *info)
 {
 	struct module_signature ms;
 	size_t sig_len, modlen = info->len;
+	int ret;
 
 	pr_devel("==>%s(,%zu)\n", __func__, modlen);
 
@@ -52,32 +29,15 @@ int mod_verify_sig(const void *mod, struct load_info *info)
 		return -EBADMSG;
 
 	memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
-	modlen -= sizeof(ms);
+
+	ret = mod_check_sig(&ms, modlen, info->name);
+	if (ret)
+		return ret;
 
 	sig_len = be32_to_cpu(ms.sig_len);
-	if (sig_len >= modlen)
-		return -EBADMSG;
-	modlen -= sig_len;
+	modlen -= sig_len + sizeof(ms);
 	info->len = modlen;
 
-	if (ms.id_type != PKEY_ID_PKCS7) {
-		pr_err("%s: Module is not signed with expected PKCS#7 message\n",
-		       info->name);
-		return -ENOPKG;
-	}
-
-	if (ms.algo != 0 ||
-	    ms.hash != 0 ||
-	    ms.signer_len != 0 ||
-	    ms.key_id_len != 0 ||
-	    ms.__pad[0] != 0 ||
-	    ms.__pad[1] != 0 ||
-	    ms.__pad[2] != 0) {
-		pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n",
-		       info->name);
-		return -EBADMSG;
-	}
-
 	return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
 				      VERIFY_USE_SECONDARY_KEYRING,
 				      VERIFYING_MODULE_SIGNATURE,
diff --git a/scripts/Makefile b/scripts/Makefile
index c42891e10ba3..3e86b300f5a1 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -17,7 +17,7 @@ hostprogs-$(CONFIG_VT)           += conmakehash
 hostprogs-$(BUILD_C_RECORDMCOUNT) += recordmcount
 hostprogs-$(CONFIG_BUILDTIME_EXTABLE_SORT) += sortextable
 hostprogs-$(CONFIG_ASN1)	 += asn1_compiler
-hostprogs-$(CONFIG_MODULE_SIG)	 += sign-file
+hostprogs-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
 hostprogs-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += extract-cert
 hostprogs-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
 
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index c352532b8f84..0bae6adb63a9 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -18,8 +18,8 @@ if INTEGRITY
 
 config INTEGRITY_SIGNATURE
 	bool "Digital signature verification using multiple keyrings"
-	depends on KEYS
 	default n
+	select KEYS
 	select SIGNATURE
 	help
 	  This option enables digital signature verification support
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 868ade3e8970..ea1aae3d07b3 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -39,11 +39,10 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
 #define restrict_link_to_ima restrict_link_by_builtin_trusted
 #endif
 
-int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
-			    const char *digest, int digestlen)
+static struct key *integrity_keyring_from_id(const unsigned int id)
 {
-	if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
-		return -EINVAL;
+	if (id >= INTEGRITY_KEYRING_MAX)
+		return ERR_PTR(-EINVAL);
 
 	if (!keyring[id]) {
 		keyring[id] =
@@ -52,23 +51,49 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			int err = PTR_ERR(keyring[id]);
 			pr_err("no %s keyring: %d\n", keyring_name[id], err);
 			keyring[id] = NULL;
-			return err;
+			return ERR_PTR(err);
 		}
 	}
 
+	return keyring[id];
+}
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+			    const char *digest, int digestlen)
+{
+	struct key *keyring;
+
+	if (siglen < 2)
+		return -EINVAL;
+
+	keyring = integrity_keyring_from_id(id);
+	if (IS_ERR(keyring))
+		return PTR_ERR(keyring);
+
 	switch (sig[1]) {
 	case 1:
 		/* v1 API expect signature without xattr type */
-		return digsig_verify(keyring[id], sig + 1, siglen - 1,
-				     digest, digestlen);
+		return digsig_verify(keyring, sig + 1, siglen - 1, digest,
+				     digestlen);
 	case 2:
-		return asymmetric_verify(keyring[id], sig, siglen,
-					 digest, digestlen);
+		return asymmetric_verify(keyring, sig, siglen, digest,
+					 digestlen);
 	}
 
 	return -EOPNOTSUPP;
 }
 
+int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig)
+{
+	struct key *keyring;
+
+	keyring = integrity_keyring_from_id(id);
+	if (IS_ERR(keyring))
+		return PTR_ERR(keyring);
+
+	return ima_modsig_verify(keyring, modsig);
+}
+
 static int __init __integrity_init_keyring(const unsigned int id,
 					   key_perm_t perm,
 					   struct key_restriction *restriction)
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 2ced99dde694..897bafc59a33 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -233,6 +233,19 @@ config IMA_APPRAISE_BOOTPARAM
 	  This option enables the different "ima_appraise=" modes
 	  (eg. fix, log) from the boot command line.
 
+config IMA_APPRAISE_MODSIG
+	bool "Support module-style signatures for appraisal"
+	depends on IMA_APPRAISE
+	depends on INTEGRITY_ASYMMETRIC_KEYS
+	select PKCS7_MESSAGE_PARSER
+	select MODULE_SIG_FORMAT
+	default n
+	help
+	   Adds support for signatures appended to files. The format of the
+	   appended signature is the same used for signed kernel modules.
+	   The modsig keyword can be used in the IMA policy to allow a hook
+	   to accept such signatures.
+
 config IMA_TRUSTED_KEYRING
 	bool "Require all keys on the .ima keyring be signed (deprecated)"
 	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index d921dc4f9eb0..31d57cdf2421 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -9,5 +9,6 @@ obj-$(CONFIG_IMA) += ima.o
 ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
 	 ima_policy.o ima_template.o ima_template_lib.o
 ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
+ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o
 ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
 obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 011b91c79351..19769bf5f6ab 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -60,6 +60,7 @@ struct ima_event_data {
 	const unsigned char *filename;
 	struct evm_ima_xattr_data *xattr_value;
 	int xattr_len;
+	const struct modsig *modsig;
 	const char *violation;
 	const void *buf;
 	int buf_len;
@@ -149,6 +150,7 @@ int template_desc_init_fields(const char *template_fmt,
 			      int *num_fields);
 struct ima_template_desc *ima_template_desc_current(void);
 struct ima_template_desc *lookup_template_desc(const char *name);
+bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
 int ima_restore_measurement_entry(struct ima_template_entry *entry);
 int ima_restore_measurement_list(loff_t bufsize, void *buf);
 int ima_measurements_show(struct seq_file *m, void *v);
@@ -196,6 +198,10 @@ enum ima_hooks {
 	__ima_hooks(__ima_hook_enumify)
 };
 
+extern const char *const func_tokens[];
+
+struct modsig;
+
 /* LIM API function definitions */
 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
 		   int mask, enum ima_hooks func, int *pcr,
@@ -203,11 +209,11 @@ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct file *file, void *buf, loff_t size,
-			    enum hash_algo algo);
+			    enum hash_algo algo, struct modsig *modsig);
 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 			   const unsigned char *filename,
 			   struct evm_ima_xattr_data *xattr_value,
-			   int xattr_len, int pcr,
+			   int xattr_len, const struct modsig *modsig, int pcr,
 			   struct ima_template_desc *template_desc);
 void ima_audit_measurement(struct integrity_iint_cache *iint,
 			   const unsigned char *filename);
@@ -249,7 +255,7 @@ int ima_appraise_measurement(enum ima_hooks func,
 			     struct integrity_iint_cache *iint,
 			     struct file *file, const unsigned char *filename,
 			     struct evm_ima_xattr_data *xattr_value,
-			     int xattr_len);
+			     int xattr_len, const struct modsig *modsig);
 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
@@ -265,7 +271,8 @@ static inline int ima_appraise_measurement(enum ima_hooks func,
 					   struct file *file,
 					   const unsigned char *filename,
 					   struct evm_ima_xattr_data *xattr_value,
-					   int xattr_len)
+					   int xattr_len,
+					   const struct modsig *modsig)
 {
 	return INTEGRITY_UNKNOWN;
 }
@@ -302,6 +309,51 @@ static inline int ima_read_xattr(struct dentry *dentry,
 
 #endif /* CONFIG_IMA_APPRAISE */
 
+#ifdef CONFIG_IMA_APPRAISE_MODSIG
+bool ima_hook_supports_modsig(enum ima_hooks func);
+int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
+		    struct modsig **modsig);
+void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
+int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
+			  const u8 **digest, u32 *digest_size);
+int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
+		       u32 *data_len);
+void ima_free_modsig(struct modsig *modsig);
+#else
+static inline bool ima_hook_supports_modsig(enum ima_hooks func)
+{
+	return false;
+}
+
+static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
+				  loff_t buf_len, struct modsig **modsig)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
+				      loff_t size)
+{
+}
+
+static inline int ima_get_modsig_digest(const struct modsig *modsig,
+					enum hash_algo *algo, const u8 **digest,
+					u32 *digest_size)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int ima_get_raw_modsig(const struct modsig *modsig,
+				     const void **data, u32 *data_len)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void ima_free_modsig(struct modsig *modsig)
+{
+}
+#endif /* CONFIG_IMA_APPRAISE_MODSIG */
+
 /* LSM based policy rules require audit */
 #ifdef CONFIG_IMA_LSM_RULES
 
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index f614e22bf39f..610759fe63b8 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -45,8 +45,8 @@ int ima_alloc_init_template(struct ima_event_data *event_data,
 	else
 		template_desc = ima_template_desc_current();
 
-	*entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
-			 sizeof(struct ima_field_data), GFP_NOFS);
+	*entry = kzalloc(struct_size(*entry, template_data,
+				     template_desc->num_fields), GFP_NOFS);
 	if (!*entry)
 		return -ENOMEM;
 
@@ -205,7 +205,7 @@ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
  */
 int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct file *file, void *buf, loff_t size,
-			    enum hash_algo algo)
+			    enum hash_algo algo, struct modsig *modsig)
 {
 	const char *audit_cause = "failed";
 	struct inode *inode = file_inode(file);
@@ -219,6 +219,14 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 		char digest[IMA_MAX_DIGEST_SIZE];
 	} hash;
 
+	/*
+	 * Always collect the modsig, because IMA might have already collected
+	 * the file digest without collecting the modsig in a previous
+	 * measurement rule.
+	 */
+	if (modsig)
+		ima_collect_modsig(modsig, buf, size);
+
 	if (iint->flags & IMA_COLLECTED)
 		goto out;
 
@@ -285,7 +293,7 @@ out:
 void ima_store_measurement(struct integrity_iint_cache *iint,
 			   struct file *file, const unsigned char *filename,
 			   struct evm_ima_xattr_data *xattr_value,
-			   int xattr_len, int pcr,
+			   int xattr_len, const struct modsig *modsig, int pcr,
 			   struct ima_template_desc *template_desc)
 {
 	static const char op[] = "add_template_measure";
@@ -297,10 +305,17 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
 					     .file = file,
 					     .filename = filename,
 					     .xattr_value = xattr_value,
-					     .xattr_len = xattr_len };
+					     .xattr_len = xattr_len,
+					     .modsig = modsig };
 	int violation = 0;
 
-	if (iint->measured_pcrs & (0x1 << pcr))
+	/*
+	 * We still need to store the measurement in the case of MODSIG because
+	 * we only have its contents to put in the list at the time of
+	 * appraisal, but a file measurement from earlier might already exist in
+	 * the measurement list.
+	 */
+	if (iint->measured_pcrs & (0x1 << pcr) && !modsig)
 		return;
 
 	result = ima_alloc_init_template(&event_data, &entry, template_desc);
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 89b83194d1dc..136ae4e0ee92 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -199,6 +199,110 @@ int ima_read_xattr(struct dentry *dentry,
 	return ret;
 }
 
+/*
+ * xattr_verify - verify xattr digest or signature
+ *
+ * Verify whether the hash or signature matches the file contents.
+ *
+ * Return 0 on success, error code otherwise.
+ */
+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)
+{
+	int rc = -EINVAL, hash_start = 0;
+
+	switch (xattr_value->type) {
+	case IMA_XATTR_DIGEST_NG:
+		/* first byte contains algorithm id */
+		hash_start = 1;
+		/* fall through */
+	case IMA_XATTR_DIGEST:
+		if (iint->flags & IMA_DIGSIG_REQUIRED) {
+			*cause = "IMA-signature-required";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
+		clear_bit(IMA_DIGSIG, &iint->atomic_flags);
+		if (xattr_len - sizeof(xattr_value->type) - hash_start >=
+				iint->ima_hash->length)
+			/*
+			 * xattr length may be longer. md5 hash in previous
+			 * version occupied 20 bytes in xattr, instead of 16
+			 */
+			rc = memcmp(&xattr_value->data[hash_start],
+				    iint->ima_hash->digest,
+				    iint->ima_hash->length);
+		else
+			rc = -EINVAL;
+		if (rc) {
+			*cause = "invalid-hash";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
+		*status = INTEGRITY_PASS;
+		break;
+	case EVM_IMA_XATTR_DIGSIG:
+		set_bit(IMA_DIGSIG, &iint->atomic_flags);
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
+					     (const char *)xattr_value,
+					     xattr_len,
+					     iint->ima_hash->digest,
+					     iint->ima_hash->length);
+		if (rc == -EOPNOTSUPP) {
+			*status = INTEGRITY_UNKNOWN;
+			break;
+		}
+		if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
+		    func == KEXEC_KERNEL_CHECK)
+			rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
+						     (const char *)xattr_value,
+						     xattr_len,
+						     iint->ima_hash->digest,
+						     iint->ima_hash->length);
+		if (rc) {
+			*cause = "invalid-signature";
+			*status = INTEGRITY_FAIL;
+		} else {
+			*status = INTEGRITY_PASS;
+		}
+		break;
+	default:
+		*status = INTEGRITY_UNKNOWN;
+		*cause = "unknown-ima-data";
+		break;
+	}
+
+	return rc;
+}
+
+/*
+ * modsig_verify - verify modsig signature
+ *
+ * Verify whether the signature matches the file contents.
+ *
+ * Return 0 on success, error code otherwise.
+ */
+static int modsig_verify(enum ima_hooks func, const struct modsig *modsig,
+			 enum integrity_status *status, const char **cause)
+{
+	int rc;
+
+	rc = integrity_modsig_verify(INTEGRITY_KEYRING_IMA, modsig);
+	if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
+	    func == KEXEC_KERNEL_CHECK)
+		rc = integrity_modsig_verify(INTEGRITY_KEYRING_PLATFORM,
+					     modsig);
+	if (rc) {
+		*cause = "invalid-signature";
+		*status = INTEGRITY_FAIL;
+	} else {
+		*status = INTEGRITY_PASS;
+	}
+
+	return rc;
+}
+
 /*
  * ima_appraise_measurement - appraise file measurement
  *
@@ -211,19 +315,22 @@ int ima_appraise_measurement(enum ima_hooks func,
 			     struct integrity_iint_cache *iint,
 			     struct file *file, const unsigned char *filename,
 			     struct evm_ima_xattr_data *xattr_value,
-			     int xattr_len)
+			     int xattr_len, const struct modsig *modsig)
 {
 	static const char op[] = "appraise_data";
 	const char *cause = "unknown";
 	struct dentry *dentry = file_dentry(file);
 	struct inode *inode = d_backing_inode(dentry);
 	enum integrity_status status = INTEGRITY_UNKNOWN;
-	int rc = xattr_len, hash_start = 0;
+	int rc = xattr_len;
+	bool try_modsig = iint->flags & IMA_MODSIG_ALLOWED && modsig;
 
-	if (!(inode->i_opflags & IOP_XATTR))
+	/* If not appraising a modsig, we need an xattr. */
+	if (!(inode->i_opflags & IOP_XATTR) && !try_modsig)
 		return INTEGRITY_UNKNOWN;
 
-	if (rc <= 0) {
+	/* If reading the xattr failed and there's no modsig, error out. */
+	if (rc <= 0 && !try_modsig) {
 		if (rc && rc != -ENODATA)
 			goto out;
 
@@ -246,6 +353,10 @@ int ima_appraise_measurement(enum ima_hooks func,
 	case INTEGRITY_UNKNOWN:
 		break;
 	case INTEGRITY_NOXATTRS:	/* No EVM protected xattrs. */
+		/* It's fine not to have xattrs when using a modsig. */
+		if (try_modsig)
+			break;
+		/* fall through */
 	case INTEGRITY_NOLABEL:		/* No security.evm xattr. */
 		cause = "missing-HMAC";
 		goto out;
@@ -256,65 +367,18 @@ int ima_appraise_measurement(enum ima_hooks func,
 		WARN_ONCE(true, "Unexpected integrity status %d\n", status);
 	}
 
-	switch (xattr_value->type) {
-	case IMA_XATTR_DIGEST_NG:
-		/* first byte contains algorithm id */
-		hash_start = 1;
-		/* fall through */
-	case IMA_XATTR_DIGEST:
-		if (iint->flags & IMA_DIGSIG_REQUIRED) {
-			cause = "IMA-signature-required";
-			status = INTEGRITY_FAIL;
-			break;
-		}
-		clear_bit(IMA_DIGSIG, &iint->atomic_flags);
-		if (xattr_len - sizeof(xattr_value->type) - hash_start >=
-				iint->ima_hash->length)
-			/* xattr length may be longer. md5 hash in previous
-			   version occupied 20 bytes in xattr, instead of 16
-			 */
-			rc = memcmp(&xattr_value->data[hash_start],
-				    iint->ima_hash->digest,
-				    iint->ima_hash->length);
-		else
-			rc = -EINVAL;
-		if (rc) {
-			cause = "invalid-hash";
-			status = INTEGRITY_FAIL;
-			break;
-		}
-		status = INTEGRITY_PASS;
-		break;
-	case EVM_IMA_XATTR_DIGSIG:
-		set_bit(IMA_DIGSIG, &iint->atomic_flags);
-		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
-					     (const char *)xattr_value,
-					     xattr_len,
-					     iint->ima_hash->digest,
-					     iint->ima_hash->length);
-		if (rc == -EOPNOTSUPP) {
-			status = INTEGRITY_UNKNOWN;
-			break;
-		}
-		if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
-		    func == KEXEC_KERNEL_CHECK)
-			rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
-						     (const char *)xattr_value,
-						     xattr_len,
-						     iint->ima_hash->digest,
-						     iint->ima_hash->length);
-		if (rc) {
-			cause = "invalid-signature";
-			status = INTEGRITY_FAIL;
-		} else {
-			status = INTEGRITY_PASS;
-		}
-		break;
-	default:
-		status = INTEGRITY_UNKNOWN;
-		cause = "unknown-ima-data";
-		break;
-	}
+	if (xattr_value)
+		rc = xattr_verify(func, iint, xattr_value, xattr_len, &status,
+				  &cause);
+
+	/*
+	 * If we have a modsig and either no imasig or the imasig's key isn't
+	 * known, then try verifying the modsig.
+	 */
+	if (try_modsig &&
+	    (!xattr_value || xattr_value->type == IMA_XATTR_DIGEST_NG ||
+	     rc == -ENOKEY))
+		rc = modsig_verify(func, modsig, &status, &cause);
 
 out:
 	/*
@@ -332,7 +396,7 @@ out:
 				    op, cause, rc, 0);
 	} else if (status != INTEGRITY_PASS) {
 		/* Fix mode, but don't replace file signatures. */
-		if ((ima_appraise & IMA_APPRAISE_FIX) &&
+		if ((ima_appraise & IMA_APPRAISE_FIX) && !try_modsig &&
 		    (!xattr_value ||
 		     xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
 			if (!ima_fix_xattr(dentry, iint))
@@ -371,7 +435,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
 	    !(iint->flags & IMA_HASH))
 		return;
 
-	rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo);
+	rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo, NULL);
 	if (rc < 0)
 		return;
 
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index d4c7b8e1b083..73044fc6a952 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -268,8 +268,16 @@ static int ima_calc_file_hash_atfm(struct file *file,
 		rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
 		rc = integrity_kernel_read(file, offset, rbuf[active],
 					   rbuf_len);
-		if (rc != rbuf_len)
+		if (rc != rbuf_len) {
+			if (rc >= 0)
+				rc = -EINVAL;
+			/*
+			 * Forward current rc, do not overwrite with return value
+			 * from ahash_wait()
+			 */
+			ahash_wait(ahash_rc, &wait);
 			goto out3;
+		}
 
 		if (rbuf[1] && offset) {
 			/* Using two buffers, and it is not the first
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 584019728660..79c01516211b 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -202,6 +202,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	int rc = 0, action, must_appraise = 0;
 	int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
 	struct evm_ima_xattr_data *xattr_value = NULL;
+	struct modsig *modsig = NULL;
 	int xattr_len = 0;
 	bool violation_check;
 	enum hash_algo hash_algo;
@@ -302,13 +303,27 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	}
 
 	if ((action & IMA_APPRAISE_SUBMASK) ||
-		    strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
+	    strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
 		/* read 'security.ima' */
 		xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
 
+		/*
+		 * Read the appended modsig if allowed by the policy, and allow
+		 * an additional measurement list entry, if needed, based on the
+		 * template format and whether the file was already measured.
+		 */
+		if (iint->flags & IMA_MODSIG_ALLOWED) {
+			rc = ima_read_modsig(func, buf, size, &modsig);
+
+			if (!rc && ima_template_has_modsig(template_desc) &&
+			    iint->flags & IMA_MEASURED)
+				action |= IMA_MEASURE;
+		}
+	}
+
 	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
 
-	rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
+	rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
 	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
 		goto out_locked;
 
@@ -317,12 +332,12 @@ static int process_measurement(struct file *file, const struct cred *cred,
 
 	if (action & IMA_MEASURE)
 		ima_store_measurement(iint, file, pathname,
-				      xattr_value, xattr_len, pcr,
+				      xattr_value, xattr_len, modsig, pcr,
 				      template_desc);
 	if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
 		inode_lock(inode);
 		rc = ima_appraise_measurement(func, iint, file, pathname,
-					      xattr_value, xattr_len);
+					      xattr_value, xattr_len, modsig);
 		inode_unlock(inode);
 		if (!rc)
 			rc = mmap_violation_check(func, file, &pathbuf,
@@ -339,6 +354,7 @@ out_locked:
 		rc = -EACCES;
 	mutex_unlock(&iint->mutex);
 	kfree(xattr_value);
+	ima_free_modsig(modsig);
 out:
 	if (pathbuf)
 		__putname(pathbuf);
diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
new file mode 100644
index 000000000000..d106885cc495
--- /dev/null
+++ b/security/integrity/ima/ima_modsig.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IMA support for appraising module-style appended signatures.
+ *
+ * Copyright (C) 2019  IBM Corporation
+ *
+ * Author:
+ * Thiago Jung Bauermann <bauerman@linux.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/module_signature.h>
+#include <keys/asymmetric-type.h>
+#include <crypto/pkcs7.h>
+
+#include "ima.h"
+
+struct modsig {
+	struct pkcs7_message *pkcs7_msg;
+
+	enum hash_algo hash_algo;
+
+	/* This digest will go in the 'd-modsig' field of the IMA template. */
+	const u8 *digest;
+	u32 digest_size;
+
+	/*
+	 * This is what will go to the measurement list if the template requires
+	 * storing the signature.
+	 */
+	int raw_pkcs7_len;
+	u8 raw_pkcs7[];
+};
+
+/**
+ * ima_hook_supports_modsig - can the policy allow modsig for this hook?
+ *
+ * modsig is only supported by hooks using ima_post_read_file(), because only
+ * they preload the contents of the file in a buffer. FILE_CHECK does that in
+ * some cases, but not when reached from vfs_open(). POLICY_CHECK can support
+ * it, but it's not useful in practice because it's a text file so deny.
+ */
+bool ima_hook_supports_modsig(enum ima_hooks func)
+{
+	switch (func) {
+	case KEXEC_KERNEL_CHECK:
+	case KEXEC_INITRAMFS_CHECK:
+	case MODULE_CHECK:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * ima_read_modsig - Read modsig from buf.
+ *
+ * Return: 0 on success, error code otherwise.
+ */
+int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
+		    struct modsig **modsig)
+{
+	const size_t marker_len = strlen(MODULE_SIG_STRING);
+	const struct module_signature *sig;
+	struct modsig *hdr;
+	size_t sig_len;
+	const void *p;
+	int rc;
+
+	if (buf_len <= marker_len + sizeof(*sig))
+		return -ENOENT;
+
+	p = buf + buf_len - marker_len;
+	if (memcmp(p, MODULE_SIG_STRING, marker_len))
+		return -ENOENT;
+
+	buf_len -= marker_len;
+	sig = (const struct module_signature *)(p - sizeof(*sig));
+
+	rc = mod_check_sig(sig, buf_len, func_tokens[func]);
+	if (rc)
+		return rc;
+
+	sig_len = be32_to_cpu(sig->sig_len);
+	buf_len -= sig_len + sizeof(*sig);
+
+	/* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */
+	hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL);
+	if (!hdr)
+		return -ENOMEM;
+
+	hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len);
+	if (IS_ERR(hdr->pkcs7_msg)) {
+		rc = PTR_ERR(hdr->pkcs7_msg);
+		kfree(hdr);
+		return rc;
+	}
+
+	memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
+	hdr->raw_pkcs7_len = sig_len;
+
+	/* We don't know the hash algorithm yet. */
+	hdr->hash_algo = HASH_ALGO__LAST;
+
+	*modsig = hdr;
+
+	return 0;
+}
+
+/**
+ * ima_collect_modsig - Calculate the file hash without the appended signature.
+ *
+ * Since the modsig is part of the file contents, the hash used in its signature
+ * isn't the same one ordinarily calculated by IMA. Therefore PKCS7 code
+ * calculates a separate one for signature verification.
+ */
+void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size)
+{
+	int rc;
+
+	/*
+	 * Provide the file contents (minus the appended sig) so that the PKCS7
+	 * code can calculate the file hash.
+	 */
+	size -= modsig->raw_pkcs7_len + strlen(MODULE_SIG_STRING) +
+		sizeof(struct module_signature);
+	rc = pkcs7_supply_detached_data(modsig->pkcs7_msg, buf, size);
+	if (rc)
+		return;
+
+	/* Ask the PKCS7 code to calculate the file hash. */
+	rc = pkcs7_get_digest(modsig->pkcs7_msg, &modsig->digest,
+			      &modsig->digest_size, &modsig->hash_algo);
+}
+
+int ima_modsig_verify(struct key *keyring, const struct modsig *modsig)
+{
+	return verify_pkcs7_message_sig(NULL, 0, modsig->pkcs7_msg, keyring,
+					VERIFYING_MODULE_SIGNATURE, NULL, NULL);
+}
+
+int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
+			  const u8 **digest, u32 *digest_size)
+{
+	*algo = modsig->hash_algo;
+	*digest = modsig->digest;
+	*digest_size = modsig->digest_size;
+
+	return 0;
+}
+
+int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
+		       u32 *data_len)
+{
+	*data = &modsig->raw_pkcs7;
+	*data_len = modsig->raw_pkcs7_len;
+
+	return 0;
+}
+
+void ima_free_modsig(struct modsig *modsig)
+{
+	if (!modsig)
+		return;
+
+	pkcs7_free_message(modsig->pkcs7_msg);
+	kfree(modsig);
+}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 6df7f641ff66..4badc4fcda98 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -6,6 +6,9 @@
  * ima_policy.c
  *	- initialize default measure policy rules
  */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/fs.h>
@@ -491,6 +494,9 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
 
+	if (template_desc)
+		*template_desc = ima_template_desc_current();
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(entry, ima_rules, list) {
 
@@ -510,6 +516,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 				action |= IMA_FAIL_UNVERIFIABLE_SIGS;
 		}
 
+
 		if (entry->action & IMA_DO_MASK)
 			actmask &= ~(entry->action | entry->action << 1);
 		else
@@ -520,8 +527,6 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 
 		if (template_desc && entry->template)
 			*template_desc = entry->template;
-		else if (template_desc)
-			*template_desc = ima_template_desc_current();
 
 		if (!actmask)
 			break;
@@ -843,6 +848,38 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
 	ima_log_string_op(ab, key, value, NULL);
 }
 
+/*
+ * Validating the appended signature included in the measurement list requires
+ * the file hash calculated without the appended signature (i.e., the 'd-modsig'
+ * field). Therefore, notify the user if they have the 'modsig' field but not
+ * the 'd-modsig' field in the template.
+ */
+static void check_template_modsig(const struct ima_template_desc *template)
+{
+#define MSG "template with 'modsig' field also needs 'd-modsig' field\n"
+	bool has_modsig, has_dmodsig;
+	static bool checked;
+	int i;
+
+	/* We only need to notify the user once. */
+	if (checked)
+		return;
+
+	has_modsig = has_dmodsig = false;
+	for (i = 0; i < template->num_fields; i++) {
+		if (!strcmp(template->fields[i]->field_id, "modsig"))
+			has_modsig = true;
+		else if (!strcmp(template->fields[i]->field_id, "d-modsig"))
+			has_dmodsig = true;
+	}
+
+	if (has_modsig && !has_dmodsig)
+		pr_notice(MSG);
+
+	checked = true;
+#undef MSG
+}
+
 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 {
 	struct audit_buffer *ab;
@@ -1128,6 +1165,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			ima_log_string(ab, "appraise_type", args[0].from);
 			if ((strcmp(args[0].from, "imasig")) == 0)
 				entry->flags |= IMA_DIGSIG_REQUIRED;
+			else if (ima_hook_supports_modsig(entry->func) &&
+				 strcmp(args[0].from, "imasig|modsig") == 0)
+				entry->flags |= IMA_DIGSIG_REQUIRED |
+						IMA_MODSIG_ALLOWED;
 			else
 				result = -EINVAL;
 			break;
@@ -1181,6 +1222,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 	else if (entry->action == APPRAISE)
 		temp_ima_appraise |= ima_appraise_flag(entry->func);
 
+	if (!result && entry->flags & IMA_MODSIG_ALLOWED) {
+		template_desc = entry->template ? entry->template :
+						  ima_template_desc_current();
+		check_template_modsig(template_desc);
+	}
+
 	audit_log_format(ab, "res=%d", !result);
 	audit_log_end(ab);
 	return result;
@@ -1252,6 +1299,12 @@ void ima_delete_rules(void)
 	}
 }
 
+#define __ima_hook_stringify(str)	(#str),
+
+const char *const func_tokens[] = {
+	__ima_hooks(__ima_hook_stringify)
+};
+
 #ifdef	CONFIG_IMA_READ_POLICY
 enum {
 	mask_exec = 0, mask_write, mask_read, mask_append
@@ -1264,12 +1317,6 @@ static const char *const mask_tokens[] = {
 	"^MAY_APPEND"
 };
 
-#define __ima_hook_stringify(str)	(#str),
-
-static const char *const func_tokens[] = {
-	__ima_hooks(__ima_hook_stringify)
-};
-
 void *ima_policy_start(struct seq_file *m, loff_t *pos)
 {
 	loff_t l = *pos;
@@ -1447,8 +1494,12 @@ 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)
-		seq_puts(m, "appraise_type=imasig ");
+	if (entry->flags & IMA_DIGSIG_REQUIRED) {
+		if (entry->flags & IMA_MODSIG_ALLOWED)
+			seq_puts(m, "appraise_type=imasig|modsig ");
+		else
+			seq_puts(m, "appraise_type=imasig ");
+	}
 	if (entry->flags & IMA_PERMIT_DIRECTIO)
 		seq_puts(m, "permit_directio ");
 	rcu_read_unlock();
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index cb349d7b2601..6aa6408603e3 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -23,6 +23,7 @@ static struct ima_template_desc builtin_templates[] = {
 	{.name = "ima-ng", .fmt = "d-ng|n-ng"},
 	{.name = "ima-sig", .fmt = "d-ng|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 = "", .fmt = ""},	/* placeholder for a custom format */
 };
 
@@ -42,6 +43,10 @@ static const struct ima_template_field supported_fields[] = {
 	 .field_show = ima_show_template_sig},
 	{.field_id = "buf", .field_init = ima_eventbuf_init,
 	 .field_show = ima_show_template_buf},
+	{.field_id = "d-modsig", .field_init = ima_eventdigest_modsig_init,
+	 .field_show = ima_show_template_digest_ng},
+	{.field_id = "modsig", .field_init = ima_eventmodsig_init,
+	 .field_show = ima_show_template_sig},
 };
 
 /*
@@ -49,10 +54,29 @@ static const struct ima_template_field supported_fields[] = {
  * need to be accounted for since they shouldn't be defined in the same template
  * description as 'd-ng' and 'n-ng' respectively.
  */
-#define MAX_TEMPLATE_NAME_LEN sizeof("d-ng|n-ng|sig|buf")
+#define MAX_TEMPLATE_NAME_LEN sizeof("d-ng|n-ng|sig|buf|d-modisg|modsig")
 
 static struct ima_template_desc *ima_template;
 
+/**
+ * ima_template_has_modsig - Check whether template has modsig-related fields.
+ * @ima_template: IMA template to check.
+ *
+ * Tells whether the given template has fields referencing a file's appended
+ * signature.
+ */
+bool ima_template_has_modsig(const struct ima_template_desc *ima_template)
+{
+	int i;
+
+	for (i = 0; i < ima_template->num_fields; i++)
+		if (!strcmp(ima_template->fields[i]->field_id, "modsig") ||
+		    !strcmp(ima_template->fields[i]->field_id, "d-modsig"))
+			return true;
+
+	return false;
+}
+
 static int __init ima_template_setup(char *str)
 {
 	struct ima_template_desc *template_desc;
@@ -282,9 +306,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc,
 	int ret = 0;
 	int i;
 
-	*entry = kzalloc(sizeof(**entry) +
-		    template_desc->num_fields * sizeof(struct ima_field_data),
-		    GFP_NOFS);
+	*entry = kzalloc(struct_size(*entry, template_data,
+				     template_desc->num_fields), GFP_NOFS);
 	if (!*entry)
 		return -ENOMEM;
 
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 2fb9a10bc6b7..32ae05d88257 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -225,7 +225,8 @@ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
 	return 0;
 }
 
-static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
+static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
+				       u8 hash_algo,
 				       struct ima_field_data *field_data)
 {
 	/*
@@ -328,6 +329,41 @@ out:
 					   hash_algo, field_data);
 }
 
+/*
+ * This function writes the digest of the file which is expected to match the
+ * digest contained in the file's appended signature.
+ */
+int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
+				struct ima_field_data *field_data)
+{
+	enum hash_algo hash_algo;
+	const u8 *cur_digest;
+	u32 cur_digestsize;
+
+	if (!event_data->modsig)
+		return 0;
+
+	if (event_data->violation) {
+		/* Recording a violation. */
+		hash_algo = HASH_ALGO_SHA1;
+		cur_digest = NULL;
+		cur_digestsize = 0;
+	} else {
+		int rc;
+
+		rc = ima_get_modsig_digest(event_data->modsig, &hash_algo,
+					   &cur_digest, &cur_digestsize);
+		if (rc)
+			return rc;
+		else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0)
+			/* There was some error collecting the digest. */
+			return -EINVAL;
+	}
+
+	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
+					   hash_algo, field_data);
+}
+
 static int ima_eventname_init_common(struct ima_event_data *event_data,
 				     struct ima_field_data *field_data,
 				     bool size_limit)
@@ -406,3 +442,29 @@ int ima_eventbuf_init(struct ima_event_data *event_data,
 					     event_data->buf_len, DATA_FMT_HEX,
 					     field_data);
 }
+
+/*
+ *  ima_eventmodsig_init - include the appended file signature as part of the
+ *  template data
+ */
+int ima_eventmodsig_init(struct ima_event_data *event_data,
+			 struct ima_field_data *field_data)
+{
+	const void *data;
+	u32 data_len;
+	int rc;
+
+	if (!event_data->modsig)
+		return 0;
+
+	/*
+	 * modsig is a runtime structure containing pointers. Get its raw data
+	 * instead.
+	 */
+	rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len);
+	if (rc)
+		return rc;
+
+	return ima_write_template_field_data(data, data_len, DATA_FMT_HEX,
+					     field_data);
+}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index 652aa5de81ef..9a88c79a7a61 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -36,10 +36,14 @@ 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_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,
 			  struct ima_field_data *field_data);
 int ima_eventsig_init(struct ima_event_data *event_data,
 		      struct ima_field_data *field_data);
 int ima_eventbuf_init(struct ima_event_data *event_data,
 		      struct ima_field_data *field_data);
+int ima_eventmodsig_init(struct ima_event_data *event_data,
+			 struct ima_field_data *field_data);
 #endif /* __LINUX_IMA_TEMPLATE_LIB_H */
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index ed12d8e13d04..d9323d31a3a8 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -31,6 +31,7 @@
 #define IMA_NEW_FILE		0x04000000
 #define EVM_IMMUTABLE_DIGSIG	0x08000000
 #define IMA_FAIL_UNVERIFIABLE_SIGS	0x10000000
+#define IMA_MODSIG_ALLOWED	0x20000000
 
 #define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
 				 IMA_HASH | IMA_APPRAISE_SUBMASK)
@@ -147,10 +148,13 @@ int integrity_kernel_read(struct file *file, loff_t offset,
 
 extern struct dentry *integrity_dir;
 
+struct modsig;
+
 #ifdef CONFIG_INTEGRITY_SIGNATURE
 
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			    const char *digest, int digestlen);
+int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
 
 int __init integrity_init_keyring(const unsigned int id);
 int __init integrity_load_x509(const unsigned int id, const char *path);
@@ -165,6 +169,12 @@ static inline int integrity_digsig_verify(const unsigned int id,
 	return -EOPNOTSUPP;
 }
 
+static inline int integrity_modsig_verify(unsigned int id,
+					  const struct modsig *modsig)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int integrity_init_keyring(const unsigned int id)
 {
 	return 0;
@@ -190,6 +200,16 @@ static inline int asymmetric_verify(struct key *keyring, const char *sig,
 }
 #endif
 
+#ifdef CONFIG_IMA_APPRAISE_MODSIG
+int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
+#else
+static inline int ima_modsig_verify(struct key *keyring,
+				    const struct modsig *modsig)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 #ifdef CONFIG_IMA_LOAD_X509
 void __init ima_load_x509(void);
 #else
diff --git a/tools/testing/selftests/kexec/test_kexec_file_load.sh b/tools/testing/selftests/kexec/test_kexec_file_load.sh
index fa7c24e8eefb..2ff600388c30 100755
--- a/tools/testing/selftests/kexec/test_kexec_file_load.sh
+++ b/tools/testing/selftests/kexec/test_kexec_file_load.sh
@@ -37,11 +37,20 @@ is_ima_sig_required()
 	# sequentially.  As a result, a policy rule may be defined, but
 	# might not necessarily be used.  This test assumes if a policy
 	# rule is specified, that is the intent.
+
+	# First check for appended signature (modsig), then xattr
 	if [ $ima_read_policy -eq 1 ]; then
 		check_ima_policy "appraise" "func=KEXEC_KERNEL_CHECK" \
-			"appraise_type=imasig"
+			"appraise_type=imasig|modsig"
 		ret=$?
-		[ $ret -eq 1 ] && log_info "IMA signature required";
+		if [ $ret -eq 1 ]; then
+			log_info "IMA or appended(modsig) signature required"
+		else
+			check_ima_policy "appraise" "func=KEXEC_KERNEL_CHECK" \
+				"appraise_type=imasig"
+			ret=$?
+			[ $ret -eq 1 ] && log_info "IMA signature required";
+		fi
 	fi
 	return $ret
 }
@@ -84,6 +93,22 @@ check_for_imasig()
 	return $ret
 }
 
+# Return 1 for appended signature (modsig) found and 0 for not found.
+check_for_modsig()
+{
+	local module_sig_string="~Module signature appended~"
+	local sig="$(tail --bytes $((${#module_sig_string} + 1)) $KERNEL_IMAGE)"
+	local ret=0
+
+	if [ "$sig" == "$module_sig_string" ]; then
+		ret=1
+		log_info "kexec kernel image modsig signed"
+	else
+		log_info "kexec kernel image not modsig signed"
+	fi
+	return $ret
+}
+
 kexec_file_load_test()
 {
 	local succeed_msg="kexec_file_load succeeded"
@@ -98,7 +123,8 @@ kexec_file_load_test()
 		# In secureboot mode with an architecture  specific
 		# policy, make sure either an IMA or PE signature exists.
 		if [ $secureboot -eq 1 ] && [ $arch_policy -eq 1 ] && \
-			[ $ima_signed -eq 0 ] && [ $pe_signed -eq 0 ]; then
+			[ $ima_signed -eq 0 ] && [ $pe_signed -eq 0 ] \
+			  && [ $ima_modsig -eq 0 ]; then
 			log_fail "$succeed_msg (missing sig)"
 		fi
 
@@ -107,7 +133,8 @@ kexec_file_load_test()
 			log_fail "$succeed_msg (missing PE sig)"
 		fi
 
-		if [ $ima_sig_required -eq 1 ] && [ $ima_signed -eq 0 ]; then
+		if [ $ima_sig_required -eq 1 ] && [ $ima_signed -eq 0 ] \
+		     && [ $ima_modsig -eq 0 ]; then
 			log_fail "$succeed_msg (missing IMA sig)"
 		fi
 
@@ -204,5 +231,8 @@ pe_signed=$?
 check_for_imasig
 ima_signed=$?
 
+check_for_modsig
+ima_modsig=$?
+
 # Test loading the kernel image via kexec_file_load syscall
 kexec_file_load_test