Resguardo inicial

linux-7.2.3/security/ipe/.gitignore

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+boot_policy.c

linux-7.2.3/security/ipe/Kconfig

@@ -0,0 +1,117 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Integrity Policy Enforcement (IPE) configuration
+#
+
+menuconfig SECURITY_IPE
+	bool "Integrity Policy Enforcement (IPE)"
+	depends on SECURITY && SECURITYFS && AUDIT && AUDITSYSCALL
+	select CRYPTO_LIB_SHA256
+	select PKCS7_MESSAGE_PARSER
+	select SYSTEM_DATA_VERIFICATION
+	select IPE_PROP_DM_VERITY if DM_VERITY
+	select IPE_PROP_DM_VERITY_SIGNATURE if DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG
+	select IPE_PROP_FS_VERITY if FS_VERITY
+	select IPE_PROP_FS_VERITY_BUILTIN_SIG if FS_VERITY && FS_VERITY_BUILTIN_SIGNATURES
+	help
+	  This option enables the Integrity Policy Enforcement LSM
+	  allowing users to define a policy to enforce a trust-based access
+	  control. A key feature of IPE is a customizable policy to allow
+	  admins to reconfigure trust requirements on the fly.
+
+	  If unsure, answer N.
+
+if SECURITY_IPE
+config IPE_BOOT_POLICY
+	string "Integrity policy to apply on system startup"
+	help
+	  This option specifies a filepath to an IPE policy that is compiled
+	  into the kernel. This policy will be enforced until a policy update
+	  is deployed via the $securityfs/ipe/policies/$policy_name/active
+	  interface.
+
+	  If unsure, leave blank.
+
+config IPE_POLICY_SIG_SECONDARY_KEYRING
+	bool "IPE policy update verification with secondary keyring"
+	default y
+	depends on SECONDARY_TRUSTED_KEYRING
+	help
+	  Also allow the secondary trusted keyring to verify IPE policy
+	  updates.
+
+	  If unsure, answer Y.
+
+config IPE_POLICY_SIG_PLATFORM_KEYRING
+	bool "IPE policy update verification with platform keyring"
+	default y
+	depends on INTEGRITY_PLATFORM_KEYRING
+	help
+	  Also allow the platform keyring to verify IPE policy updates.
+
+	  If unsure, answer Y.
+
+menu "IPE Trust Providers"
+
+config IPE_PROP_DM_VERITY
+	bool "Enable support for dm-verity based on root hash"
+	depends on DM_VERITY
+	help
+	  This option enables the 'dmverity_roothash' property within IPE
+	  policies. The property evaluates to TRUE when a file from a dm-verity
+	  volume is evaluated, and the volume's root hash matches the value
+	  supplied in the policy.
+
+config IPE_PROP_DM_VERITY_SIGNATURE
+	bool "Enable support for dm-verity based on root hash signature"
+	depends on DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG
+	help
+	  This option enables the 'dmverity_signature' property within IPE
+	  policies. The property evaluates to TRUE when a file from a dm-verity
+	  volume, which has been mounted with a valid signed root hash,
+	  is evaluated.
+
+	  If unsure, answer Y.
+
+config IPE_PROP_FS_VERITY
+	bool "Enable support for fs-verity based on file digest"
+	depends on FS_VERITY
+	help
+	  This option enables the 'fsverity_digest' property within IPE
+	  policies. The property evaluates to TRUE when a file is fsverity
+	  enabled and its digest matches the supplied digest value in the
+	  policy.
+
+	  if unsure, answer Y.
+
+config IPE_PROP_FS_VERITY_BUILTIN_SIG
+	bool "Enable support for fs-verity based on builtin signature"
+	depends on FS_VERITY && FS_VERITY_BUILTIN_SIGNATURES
+	help
+	  This option enables the 'fsverity_signature' property within IPE
+	  policies. The property evaluates to TRUE when a file is fsverity
+	  enabled and it has a valid builtin signature whose signing cert
+	  is in the .fs-verity keyring.
+
+	  if unsure, answer Y.
+
+endmenu
+
+config SECURITY_IPE_KUNIT_TEST
+	bool "Build KUnit tests for IPE" if !KUNIT_ALL_TESTS
+	depends on KUNIT=y
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the IPE KUnit tests.
+
+	  KUnit tests run during boot and output the results to the debug log
+	  in TAP format (https://testanything.org/). Only useful for kernel devs
+	  running KUnit test harness and are not for inclusion into a
+	  production build.
+
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
+endif

linux-7.2.3/security/ipe/Makefile

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+#
+# Makefile for building the IPE module as part of the kernel tree.
+#
+
+quiet_cmd_polgen = IPE_POL $(2)
+      cmd_polgen = scripts/ipe/polgen/polgen security/ipe/boot_policy.c $(2)
+
+targets += boot_policy.c
+
+$(obj)/boot_policy.c: scripts/ipe/polgen/polgen $(CONFIG_IPE_BOOT_POLICY) FORCE
+	$(call if_changed,polgen,$(CONFIG_IPE_BOOT_POLICY))
+
+obj-$(CONFIG_SECURITY_IPE) += \
+	boot_policy.o \
+	digest.o \
+	eval.o \
+	hooks.o \
+	fs.o \
+	ipe.o \
+	policy.o \
+	policy_fs.o \
+	policy_parser.o \
+	audit.o \
+
+clean-files := boot_policy.c \
+
+obj-$(CONFIG_SECURITY_IPE_KUNIT_TEST) += \
+	policy_tests.o \

linux-7.2.3/security/ipe/audit.c

@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/audit.h>
+#include <linux/types.h>
+#include <crypto/sha2.h>
+
+#include "ipe.h"
+#include "eval.h"
+#include "hooks.h"
+#include "policy.h"
+#include "audit.h"
+#include "digest.h"
+
+#define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY")
+
+#define IPE_AUDIT_HASH_ALG "sha256" /* keep in sync with audit_policy() */
+
+#define AUDIT_POLICY_LOAD_FMT "policy_name=\"%s\" policy_version=%hu.%hu.%hu "\
+			      "policy_digest=" IPE_AUDIT_HASH_ALG ":"
+#define AUDIT_POLICY_LOAD_NULL_FMT "policy_name=? policy_version=? "\
+				   "policy_digest=?"
+#define AUDIT_OLD_ACTIVE_POLICY_FMT "old_active_pol_name=\"%s\" "\
+				    "old_active_pol_version=%hu.%hu.%hu "\
+				    "old_policy_digest=" IPE_AUDIT_HASH_ALG ":"
+#define AUDIT_OLD_ACTIVE_POLICY_NULL_FMT "old_active_pol_name=? "\
+					 "old_active_pol_version=? "\
+					 "old_policy_digest=?"
+#define AUDIT_NEW_ACTIVE_POLICY_FMT "new_active_pol_name=\"%s\" "\
+				    "new_active_pol_version=%hu.%hu.%hu "\
+				    "new_policy_digest=" IPE_AUDIT_HASH_ALG ":"
+
+static const char *const audit_op_names[__IPE_OP_MAX + 1] = {
+	"EXECUTE",
+	"FIRMWARE",
+	"KMODULE",
+	"KEXEC_IMAGE",
+	"KEXEC_INITRAMFS",
+	"POLICY",
+	"X509_CERT",
+	"UNKNOWN",
+};
+
+static const char *const audit_hook_names[__IPE_HOOK_MAX] = {
+	"BPRM_CHECK",
+	"BPRM_CREDS_FOR_EXEC",
+	"MMAP",
+	"MPROTECT",
+	"KERNEL_READ",
+	"KERNEL_LOAD",
+};
+
+static const char *const audit_prop_names[__IPE_PROP_MAX] = {
+	"boot_verified=FALSE",
+	"boot_verified=TRUE",
+	"dmverity_roothash=",
+	"dmverity_signature=FALSE",
+	"dmverity_signature=TRUE",
+	"fsverity_digest=",
+	"fsverity_signature=FALSE",
+	"fsverity_signature=TRUE",
+};
+
+/**
+ * audit_dmv_roothash() - audit the roothash of a dmverity_roothash property.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @rh: Supplies a pointer to the digest structure.
+ */
+static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh)
+{
+	audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_DMV_ROOTHASH]);
+	ipe_digest_audit(ab, rh);
+}
+
+/**
+ * audit_fsv_digest() - audit the digest of a fsverity_digest property.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @d: Supplies a pointer to the digest structure.
+ */
+static void audit_fsv_digest(struct audit_buffer *ab, const void *d)
+{
+	audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_FSV_DIGEST]);
+	ipe_digest_audit(ab, d);
+}
+
+/**
+ * audit_rule() - audit an IPE policy rule.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @r: Supplies a pointer to the ipe_rule to approximate a string form for.
+ */
+static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r)
+{
+	const struct ipe_prop *ptr;
+
+	audit_log_format(ab, " rule=\"op=%s ", audit_op_names[r->op]);
+
+	list_for_each_entry(ptr, &r->props, next) {
+		switch (ptr->type) {
+		case IPE_PROP_DMV_ROOTHASH:
+			audit_dmv_roothash(ab, ptr->value);
+			break;
+		case IPE_PROP_FSV_DIGEST:
+			audit_fsv_digest(ab, ptr->value);
+			break;
+		default:
+			audit_log_format(ab, "%s", audit_prop_names[ptr->type]);
+			break;
+		}
+
+		audit_log_format(ab, " ");
+	}
+
+	audit_log_format(ab, "action=%s\"", ACTSTR(r->action));
+}
+
+/**
+ * ipe_audit_match() - Audit a rule match in a policy evaluation.
+ * @ctx: Supplies a pointer to the evaluation context that was used in the
+ *	 evaluation.
+ * @match_type: Supplies the scope of the match: rule, operation default,
+ *		global default.
+ * @act: Supplies the IPE's evaluation decision, deny or allow.
+ * @r: Supplies a pointer to the rule that was matched, if possible.
+ */
+void ipe_audit_match(const struct ipe_eval_ctx *const ctx,
+		     enum ipe_match match_type,
+		     enum ipe_action_type act, const struct ipe_rule *const r)
+{
+	const char *op = audit_op_names[ctx->op];
+	char comm[sizeof(current->comm)];
+	struct audit_buffer *ab;
+	struct inode *inode;
+
+	if (act != IPE_ACTION_DENY && !READ_ONCE(success_audit))
+		return;
+
+	ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN,
+			     AUDIT_IPE_ACCESS);
+	if (!ab)
+		return;
+
+	audit_log_format(ab, "ipe_op=%s ipe_hook=%s enforcing=%d pid=%d comm=",
+			 op, audit_hook_names[ctx->hook], READ_ONCE(enforce),
+			 task_tgid_nr(current));
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
+
+	if (ctx->file) {
+		audit_log_d_path(ab, " path=", &ctx->file->f_path);
+		inode = file_inode(ctx->file);
+		if (inode) {
+			audit_log_format(ab, " dev=");
+			audit_log_untrustedstring(ab, inode->i_sb->s_id);
+			audit_log_format(ab, " ino=%llu", inode->i_ino);
+		} else {
+			audit_log_format(ab, " dev=? ino=?");
+		}
+	} else {
+		audit_log_format(ab, " path=? dev=? ino=?");
+	}
+
+	if (match_type == IPE_MATCH_RULE)
+		audit_rule(ab, r);
+	else if (match_type == IPE_MATCH_TABLE)
+		audit_log_format(ab, " rule=\"DEFAULT op=%s action=%s\"", op,
+				 ACTSTR(act));
+	else
+		audit_log_format(ab, " rule=\"DEFAULT action=%s\"",
+				 ACTSTR(act));
+
+	audit_log_end(ab);
+}
+
+/**
+ * audit_policy() - Audit a policy's name, version and thumbprint to @ab.
+ * @ab: Supplies a pointer to the audit buffer to append to.
+ * @audit_format: Supplies a pointer to the audit format string
+ * @p: Supplies a pointer to the policy to audit.
+ */
+static void audit_policy(struct audit_buffer *ab,
+			 const char *audit_format,
+			 const struct ipe_policy *const p)
+{
+	u8 digest[SHA256_DIGEST_SIZE];
+
+	sha256(p->pkcs7, p->pkcs7len, digest);
+
+	audit_log_format(ab, audit_format, p->parsed->name,
+			 p->parsed->version.major, p->parsed->version.minor,
+			 p->parsed->version.rev);
+	audit_log_n_hex(ab, digest, sizeof(digest));
+}
+
+/**
+ * ipe_audit_policy_activation() - Audit a policy being activated.
+ * @op: Supplies a pointer to the previously activated policy to audit.
+ * @np: Supplies a pointer to the newly activated policy to audit.
+ */
+void ipe_audit_policy_activation(const struct ipe_policy *const op,
+				 const struct ipe_policy *const np)
+{
+	struct audit_buffer *ab;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL,
+			     AUDIT_IPE_CONFIG_CHANGE);
+	if (!ab)
+		return;
+
+	if (op) {
+		audit_policy(ab, AUDIT_OLD_ACTIVE_POLICY_FMT, op);
+		audit_log_format(ab, " ");
+	} else {
+		/*
+		 * old active policy can be NULL if there is no kernel
+		 * built-in policy
+		 */
+		audit_log_format(ab, AUDIT_OLD_ACTIVE_POLICY_NULL_FMT);
+		audit_log_format(ab, " ");
+	}
+	audit_policy(ab, AUDIT_NEW_ACTIVE_POLICY_FMT, np);
+	audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=1",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current));
+
+	audit_log_end(ab);
+}
+
+/**
+ * ipe_audit_policy_load() - Audit a policy loading event.
+ * @p: Supplies a pointer to the policy to audit or an error pointer.
+ */
+void ipe_audit_policy_load(const struct ipe_policy *const p)
+{
+	struct audit_buffer *ab;
+	int err = 0;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL,
+			     AUDIT_IPE_POLICY_LOAD);
+	if (!ab)
+		return;
+
+	if (!IS_ERR(p)) {
+		audit_policy(ab, AUDIT_POLICY_LOAD_FMT, p);
+	} else {
+		audit_log_format(ab, AUDIT_POLICY_LOAD_NULL_FMT);
+		err = PTR_ERR(p);
+	}
+
+	audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=%d errno=%d",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current), !err, err);
+
+	audit_log_end(ab);
+}
+
+/**
+ * ipe_audit_enforce() - Audit a change in IPE's enforcement state.
+ * @new_enforce: The new value enforce to be set.
+ * @old_enforce: The old value currently in enforce.
+ */
+void ipe_audit_enforce(bool new_enforce, bool old_enforce)
+{
+	struct audit_buffer *ab;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS);
+	if (!ab)
+		return;
+
+	audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
+		  "enforcing=%d old_enforcing=%d auid=%u ses=%u"
+		  " enabled=1 old-enabled=1 lsm=ipe res=1",
+		  new_enforce, old_enforce,
+		  from_kuid(&init_user_ns, audit_get_loginuid(current)),
+		  audit_get_sessionid(current));
+
+	audit_log_end(ab);
+}

linux-7.2.3/security/ipe/audit.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_AUDIT_H
+#define _IPE_AUDIT_H
+
+#include "policy.h"
+
+void ipe_audit_match(const struct ipe_eval_ctx *const ctx,
+		     enum ipe_match match_type,
+		     enum ipe_action_type act, const struct ipe_rule *const r);
+void ipe_audit_policy_load(const struct ipe_policy *const p);
+void ipe_audit_policy_activation(const struct ipe_policy *const op,
+				 const struct ipe_policy *const np);
+void ipe_audit_enforce(bool new_enforce, bool old_enforce);
+
+#endif /* _IPE_AUDIT_H */

linux-7.2.3/security/ipe/digest.c

@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/hex.h>
+#include "digest.h"
+
+/**
+ * ipe_digest_parse() - parse a digest in IPE's policy.
+ * @valstr: Supplies the string parsed from the policy.
+ *
+ * Digests in IPE are defined in a standard way:
+ *	<alg_name>:<hex>
+ *
+ * Use this function to create a property to parse the digest
+ * consistently. The parsed digest will be saved in @value in IPE's
+ * policy.
+ *
+ * Return: The parsed digest_info structure on success. If an error occurs,
+ * the function will return the error value (via ERR_PTR).
+ */
+struct digest_info *ipe_digest_parse(const char *valstr)
+{
+	struct digest_info *info = NULL;
+	char *sep, *raw_digest;
+	size_t raw_digest_len;
+	u8 *digest = NULL;
+	char *alg = NULL;
+	int rc = 0;
+
+	info = kzalloc_obj(*info);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	sep = strchr(valstr, ':');
+	if (!sep) {
+		rc = -EBADMSG;
+		goto err;
+	}
+
+	alg = kstrndup(valstr, sep - valstr, GFP_KERNEL);
+	if (!alg) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	raw_digest = sep + 1;
+	raw_digest_len = strlen(raw_digest);
+
+	info->digest_len = (raw_digest_len + 1) / 2;
+	digest = kzalloc(info->digest_len, GFP_KERNEL);
+	if (!digest) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	rc = hex2bin(digest, raw_digest, info->digest_len);
+	if (rc < 0) {
+		rc = -EINVAL;
+		goto err;
+	}
+
+	info->alg = alg;
+	info->digest = digest;
+	return info;
+
+err:
+	kfree(alg);
+	kfree(digest);
+	kfree(info);
+	return ERR_PTR(rc);
+}
+
+/**
+ * ipe_digest_eval() - evaluate an IPE digest against another digest.
+ * @expected: Supplies the policy-provided digest value.
+ * @digest: Supplies the digest to compare against the policy digest value.
+ *
+ * Return:
+ * * %true	- digests match
+ * * %false	- digests do not match
+ */
+bool ipe_digest_eval(const struct digest_info *expected,
+		     const struct digest_info *digest)
+{
+	return (expected->digest_len == digest->digest_len) &&
+	       (!strcmp(expected->alg, digest->alg)) &&
+	       (!memcmp(expected->digest, digest->digest, expected->digest_len));
+}
+
+/**
+ * ipe_digest_free() - free an IPE digest.
+ * @info: Supplies a pointer the policy-provided digest to free.
+ */
+void ipe_digest_free(struct digest_info *info)
+{
+	if (IS_ERR_OR_NULL(info))
+		return;
+
+	kfree(info->alg);
+	kfree(info->digest);
+	kfree(info);
+}
+
+/**
+ * ipe_digest_audit() - audit a digest that was sourced from IPE's policy.
+ * @ab: Supplies the audit_buffer to append the formatted result.
+ * @info: Supplies a pointer to source the audit record from.
+ *
+ * Digests in IPE are audited in this format:
+ *	<alg_name>:<hex>
+ */
+void ipe_digest_audit(struct audit_buffer *ab, const struct digest_info *info)
+{
+	audit_log_untrustedstring(ab, info->alg);
+	audit_log_format(ab, ":");
+	audit_log_n_hex(ab, info->digest, info->digest_len);
+}

linux-7.2.3/security/ipe/digest.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_DIGEST_H
+#define _IPE_DIGEST_H
+
+#include <linux/types.h>
+#include <linux/audit.h>
+
+#include "policy.h"
+
+struct digest_info {
+	const char *alg;
+	const u8 *digest;
+	size_t digest_len;
+};
+
+struct digest_info *ipe_digest_parse(const char *valstr);
+void ipe_digest_free(struct digest_info *digest_info);
+void ipe_digest_audit(struct audit_buffer *ab, const struct digest_info *val);
+bool ipe_digest_eval(const struct digest_info *expected,
+		     const struct digest_info *digest);
+
+#endif /* _IPE_DIGEST_H */

linux-7.2.3/security/ipe/eval.c

@@ -0,0 +1,393 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/sched.h>
+#include <linux/rcupdate.h>
+#include <linux/moduleparam.h>
+#include <linux/fsverity.h>
+
+#include "ipe.h"
+#include "eval.h"
+#include "policy.h"
+#include "audit.h"
+#include "digest.h"
+
+struct ipe_policy __rcu *ipe_active_policy;
+bool success_audit;
+bool enforce = true;
+#define INO_BLOCK_DEV(ino) ((ino)->i_sb->s_bdev)
+
+#define FILE_SUPERBLOCK(f) ((f)->f_path.mnt->mnt_sb)
+
+/**
+ * build_ipe_sb_ctx() - Build initramfs field of an ipe evaluation context.
+ * @ctx: Supplies a pointer to the context to be populated.
+ * @file: Supplies the file struct of the file triggered IPE event.
+ */
+static void build_ipe_sb_ctx(struct ipe_eval_ctx *ctx, const struct file *const file)
+{
+	ctx->initramfs = ipe_sb(FILE_SUPERBLOCK(file))->initramfs;
+}
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+/**
+ * build_ipe_bdev_ctx() - Build ipe_bdev field of an evaluation context.
+ * @ctx: Supplies a pointer to the context to be populated.
+ * @ino: Supplies the inode struct of the file triggered IPE event.
+ */
+static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino)
+{
+	if (INO_BLOCK_DEV(ino))
+		ctx->ipe_bdev = ipe_bdev(INO_BLOCK_DEV(ino));
+}
+#else
+static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino)
+{
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+static void build_ipe_inode_blob_ctx(struct ipe_eval_ctx *ctx,
+				     const struct inode *const ino)
+{
+	ctx->ipe_inode = ipe_inode(ctx->ino);
+}
+#else
+static inline void build_ipe_inode_blob_ctx(struct ipe_eval_ctx *ctx,
+					    const struct inode *const ino)
+{
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+/**
+ * build_ipe_inode_ctx() - Build inode fields of an evaluation context.
+ * @ctx: Supplies a pointer to the context to be populated.
+ * @ino: Supplies the inode struct of the file triggered IPE event.
+ */
+static void build_ipe_inode_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino)
+{
+	ctx->ino = ino;
+	build_ipe_inode_blob_ctx(ctx, ino);
+}
+#else
+static void build_ipe_inode_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino)
+{
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY */
+
+/**
+ * ipe_build_eval_ctx() - Build an ipe evaluation context.
+ * @ctx: Supplies a pointer to the context to be populated.
+ * @file: Supplies a pointer to the file to associated with the evaluation.
+ * @op: Supplies the IPE policy operation associated with the evaluation.
+ * @hook: Supplies the LSM hook associated with the evaluation.
+ */
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+			const struct file *file,
+			enum ipe_op_type op,
+			enum ipe_hook_type hook)
+{
+	struct inode *ino;
+
+	ctx->file = file;
+	ctx->op = op;
+	ctx->hook = hook;
+
+	if (file) {
+		build_ipe_sb_ctx(ctx, file);
+		ino = d_real_inode(file->f_path.dentry);
+		build_ipe_bdev_ctx(ctx, ino);
+		build_ipe_inode_ctx(ctx, ino);
+	}
+}
+
+/**
+ * evaluate_boot_verified() - Evaluate @ctx for the boot verified property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the @p
+ * * %false	- The current @ctx doesn't match the @p
+ */
+static bool evaluate_boot_verified(const struct ipe_eval_ctx *const ctx)
+{
+	return ctx->initramfs;
+}
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+/**
+ * evaluate_dmv_roothash() - Evaluate @ctx against a dmv roothash property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ * @p: Supplies a pointer to the property being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the @p
+ * * %false	- The current @ctx doesn't match the @p
+ */
+static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx,
+				  struct ipe_prop *p)
+{
+	return !!ctx->ipe_bdev &&
+	       !!ctx->ipe_bdev->root_hash &&
+	       ipe_digest_eval(p->value,
+			       ctx->ipe_bdev->root_hash);
+}
+#else
+static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx,
+				  struct ipe_prop *p)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE
+/**
+ * evaluate_dmv_sig_false() - Evaluate @ctx against a dmv sig false property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the property
+ * * %false	- The current @ctx doesn't match the property
+ */
+static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx)
+{
+	return !ctx->ipe_bdev || (!ctx->ipe_bdev->dm_verity_signed);
+}
+
+/**
+ * evaluate_dmv_sig_true() - Evaluate @ctx against a dmv sig true property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the property
+ * * %false	- The current @ctx doesn't match the property
+ */
+static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx)
+{
+	return !evaluate_dmv_sig_false(ctx);
+}
+#else
+static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx)
+{
+	return false;
+}
+
+static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY
+/**
+ * evaluate_fsv_digest() - Evaluate @ctx against a fsv digest property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ * @p: Supplies a pointer to the property being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the @p
+ * * %false	- The current @ctx doesn't match the @p
+ */
+static bool evaluate_fsv_digest(const struct ipe_eval_ctx *const ctx,
+				struct ipe_prop *p)
+{
+	enum hash_algo alg;
+	u8 digest[FS_VERITY_MAX_DIGEST_SIZE];
+	struct digest_info info;
+
+	if (!ctx->ino)
+		return false;
+	if (!fsverity_get_digest((struct inode *)ctx->ino,
+				 digest,
+				 NULL,
+				 &alg))
+		return false;
+
+	info.alg = hash_algo_name[alg];
+	info.digest = digest;
+	info.digest_len = hash_digest_size[alg];
+
+	return ipe_digest_eval(p->value, &info);
+}
+#else
+static bool evaluate_fsv_digest(const struct ipe_eval_ctx *const ctx,
+				struct ipe_prop *p)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+/**
+ * evaluate_fsv_sig_false() - Evaluate @ctx against a fsv sig false property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ *
+ * Return:
+ * * %true	- The current @ctx match the property
+ * * %false	- The current @ctx doesn't match the property
+ */
+static bool evaluate_fsv_sig_false(const struct ipe_eval_ctx *const ctx)
+{
+	return !ctx->ino ||
+	       !IS_VERITY(ctx->ino) ||
+	       !ctx->ipe_inode ||
+	       !ctx->ipe_inode->fs_verity_signed;
+}
+
+/**
+ * evaluate_fsv_sig_true() - Evaluate @ctx against a fsv sig true property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ *
+ * Return:
+ * * %true - The current @ctx match the property
+ * * %false - The current @ctx doesn't match the property
+ */
+static bool evaluate_fsv_sig_true(const struct ipe_eval_ctx *const ctx)
+{
+	return !evaluate_fsv_sig_false(ctx);
+}
+#else
+static bool evaluate_fsv_sig_false(const struct ipe_eval_ctx *const ctx)
+{
+	return false;
+}
+
+static bool evaluate_fsv_sig_true(const struct ipe_eval_ctx *const ctx)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+/**
+ * evaluate_property() - Analyze @ctx against a rule property.
+ * @ctx: Supplies a pointer to the context to be evaluated.
+ * @p: Supplies a pointer to the property to be evaluated.
+ *
+ * This function Determines whether the specified @ctx
+ * matches the conditions defined by a rule property @p.
+ *
+ * Return:
+ * * %true	- The current @ctx match the @p
+ * * %false	- The current @ctx doesn't match the @p
+ */
+static bool evaluate_property(const struct ipe_eval_ctx *const ctx,
+			      struct ipe_prop *p)
+{
+	switch (p->type) {
+	case IPE_PROP_BOOT_VERIFIED_FALSE:
+		return !evaluate_boot_verified(ctx);
+	case IPE_PROP_BOOT_VERIFIED_TRUE:
+		return evaluate_boot_verified(ctx);
+	case IPE_PROP_DMV_ROOTHASH:
+		return evaluate_dmv_roothash(ctx, p);
+	case IPE_PROP_DMV_SIG_FALSE:
+		return evaluate_dmv_sig_false(ctx);
+	case IPE_PROP_DMV_SIG_TRUE:
+		return evaluate_dmv_sig_true(ctx);
+	case IPE_PROP_FSV_DIGEST:
+		return evaluate_fsv_digest(ctx, p);
+	case IPE_PROP_FSV_SIG_FALSE:
+		return evaluate_fsv_sig_false(ctx);
+	case IPE_PROP_FSV_SIG_TRUE:
+		return evaluate_fsv_sig_true(ctx);
+	default:
+		return false;
+	}
+}
+
+/**
+ * ipe_evaluate_event() - Analyze @ctx against the current active policy.
+ * @ctx: Supplies a pointer to the context to be evaluated.
+ *
+ * This is the loop where all policy evaluations happen against the IPE policy.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- @ctx did not pass evaluation
+ */
+int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx)
+{
+	const struct ipe_op_table *rules = NULL;
+	const struct ipe_rule *rule = NULL;
+	struct ipe_policy *pol = NULL;
+	struct ipe_prop *prop = NULL;
+	enum ipe_action_type action;
+	enum ipe_match match_type;
+	bool match = false;
+	int rc = 0;
+
+	rcu_read_lock();
+
+	pol = rcu_dereference(ipe_active_policy);
+	if (!pol) {
+		rcu_read_unlock();
+		return 0;
+	}
+
+	if (ctx->op == IPE_OP_INVALID) {
+		if (pol->parsed->global_default_action == IPE_ACTION_INVALID) {
+			WARN(1, "no default rule set for unknown op, ALLOW it");
+			action = IPE_ACTION_ALLOW;
+		} else {
+			action = pol->parsed->global_default_action;
+		}
+		match_type = IPE_MATCH_GLOBAL;
+		goto eval;
+	}
+
+	rules = &pol->parsed->rules[ctx->op];
+
+	list_for_each_entry(rule, &rules->rules, next) {
+		match = true;
+
+		list_for_each_entry(prop, &rule->props, next) {
+			match = evaluate_property(ctx, prop);
+			if (!match)
+				break;
+		}
+
+		if (match)
+			break;
+	}
+
+	if (match) {
+		action = rule->action;
+		match_type = IPE_MATCH_RULE;
+	} else if (rules->default_action != IPE_ACTION_INVALID) {
+		action = rules->default_action;
+		match_type = IPE_MATCH_TABLE;
+	} else {
+		action = pol->parsed->global_default_action;
+		match_type = IPE_MATCH_GLOBAL;
+	}
+
+eval:
+	ipe_audit_match(ctx, match_type, action, rule);
+	rcu_read_unlock();
+
+	if (action == IPE_ACTION_DENY)
+		rc = -EACCES;
+
+	if (!READ_ONCE(enforce))
+		rc = 0;
+
+	return rc;
+}
+
+/* Set the right module name */
+#ifdef KBUILD_MODNAME
+#undef KBUILD_MODNAME
+#define KBUILD_MODNAME "ipe"
+#endif
+
+module_param(success_audit, bool, 0400);
+MODULE_PARM_DESC(success_audit, "Start IPE with success auditing enabled");
+module_param(enforce, bool, 0400);
+MODULE_PARM_DESC(enforce, "Start IPE in enforce or permissive mode");

linux-7.2.3/security/ipe/eval.h

@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_EVAL_H
+#define _IPE_EVAL_H
+
+#include <linux/file.h>
+#include <linux/types.h>
+
+#include "policy.h"
+#include "hooks.h"
+
+#define IPE_EVAL_CTX_INIT ((struct ipe_eval_ctx){ 0 })
+
+extern struct ipe_policy __rcu *ipe_active_policy;
+extern bool success_audit;
+extern bool enforce;
+
+struct ipe_superblock {
+	bool initramfs;
+};
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+struct ipe_bdev {
+#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE
+	bool dm_verity_signed;
+#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */
+	struct digest_info *root_hash;
+};
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+struct ipe_inode {
+	bool fs_verity_signed;
+};
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+struct ipe_eval_ctx {
+	enum ipe_op_type op;
+	enum ipe_hook_type hook;
+
+	const struct file *file;
+	bool initramfs;
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+	const struct ipe_bdev *ipe_bdev;
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY
+	const struct inode *ino;
+#endif /* CONFIG_IPE_PROP_FS_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+	const struct ipe_inode *ipe_inode;
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+};
+
+enum ipe_match {
+	IPE_MATCH_RULE = 0,
+	IPE_MATCH_TABLE,
+	IPE_MATCH_GLOBAL,
+	__IPE_MATCH_MAX
+};
+
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+			const struct file *file,
+			enum ipe_op_type op,
+			enum ipe_hook_type hook);
+int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx);
+
+#endif /* _IPE_EVAL_H */

linux-7.2.3/security/ipe/fs.c

@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/dcache.h>
+#include <linux/security.h>
+
+#include "ipe.h"
+#include "fs.h"
+#include "eval.h"
+#include "policy.h"
+#include "audit.h"
+
+static struct dentry *root __ro_after_init;
+struct dentry *policy_root __ro_after_init;
+
+/**
+ * setaudit() - Write handler for the securityfs node, "ipe/success_audit"
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission
+ */
+static ssize_t setaudit(struct file *f, const char __user *data,
+			size_t len, loff_t *offset)
+{
+	int rc = 0;
+	bool value;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	rc = kstrtobool_from_user(data, len, &value);
+	if (rc)
+		return rc;
+
+	WRITE_ONCE(success_audit, value);
+
+	return len;
+}
+
+/**
+ * getaudit() - Read handler for the securityfs node, "ipe/success_audit"
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the read syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return: Length of buffer written
+ */
+static ssize_t getaudit(struct file *f, char __user *data,
+			size_t len, loff_t *offset)
+{
+	const char *result;
+
+	result = ((READ_ONCE(success_audit)) ? "1" : "0");
+
+	return simple_read_from_buffer(data, len, offset, result, 1);
+}
+
+/**
+ * setenforce() - Write handler for the securityfs node, "ipe/enforce"
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission
+ */
+static ssize_t setenforce(struct file *f, const char __user *data,
+			  size_t len, loff_t *offset)
+{
+	int rc = 0;
+	bool new_value, old_value;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	old_value = READ_ONCE(enforce);
+	rc = kstrtobool_from_user(data, len, &new_value);
+	if (rc)
+		return rc;
+
+	if (new_value != old_value) {
+		ipe_audit_enforce(new_value, old_value);
+		WRITE_ONCE(enforce, new_value);
+	}
+
+	return len;
+}
+
+/**
+ * getenforce() - Read handler for the securityfs node, "ipe/enforce"
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the read syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return: Length of buffer written
+ */
+static ssize_t getenforce(struct file *f, char __user *data,
+			  size_t len, loff_t *offset)
+{
+	const char *result;
+
+	result = ((READ_ONCE(enforce)) ? "1" : "0");
+
+	return simple_read_from_buffer(data, len, offset, result, 1);
+}
+
+/**
+ * new_policy() - Write handler for the securityfs node, "ipe/new_policy".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission
+ * * %-ENOMEM			- Out of memory (OOM)
+ * * %-EBADMSG			- Policy is invalid
+ * * %-ERANGE			- Policy version number overflow
+ * * %-EINVAL			- Policy version parsing error
+ * * %-EEXIST			- Same name policy already deployed
+ * * %-ENOKEY			- Policy signing key not found
+ * * %-EKEYREJECTED		- Policy signature verification failed
+ */
+static ssize_t new_policy(struct file *f, const char __user *data,
+			  size_t len, loff_t *offset)
+{
+	struct ipe_policy *p = NULL;
+	char *copy = NULL;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) {
+		rc = -EPERM;
+		goto out;
+	}
+
+	copy = memdup_user_nul(data, len);
+	if (IS_ERR(copy)) {
+		rc = PTR_ERR(copy);
+		copy = NULL;
+		goto out;
+	}
+
+	p = ipe_new_policy(NULL, 0, copy, len);
+	if (IS_ERR(p)) {
+		rc = PTR_ERR(p);
+		goto out;
+	}
+
+	rc = ipe_new_policyfs_node(p);
+	if (rc)
+		goto out;
+
+out:
+	kfree(copy);
+	if (rc < 0) {
+		ipe_free_policy(p);
+		ipe_audit_policy_load(ERR_PTR(rc));
+	} else {
+		ipe_audit_policy_load(p);
+	}
+	return (rc < 0) ? rc : len;
+}
+
+static const struct file_operations np_fops = {
+	.write = new_policy,
+};
+
+static const struct file_operations audit_fops = {
+	.write = setaudit,
+	.read = getaudit,
+};
+
+static const struct file_operations enforce_fops = {
+	.write = setenforce,
+	.read = getenforce,
+};
+
+/**
+ * ipe_init_securityfs() - Initialize IPE's securityfs tree at fsinit.
+ *
+ * Return: %0 on success. If an error occurs, the function will return
+ * the -errno.
+ */
+int __init ipe_init_securityfs(void)
+{
+	int rc = 0;
+	struct ipe_policy *ap;
+	struct dentry *dentry;
+
+	if (!ipe_enabled)
+		return -EOPNOTSUPP;
+
+	root = securityfs_create_dir("ipe", NULL);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	dentry = securityfs_create_file("success_audit", 0600, root,
+					    NULL, &audit_fops);
+	if (IS_ERR(dentry)) {
+		rc = PTR_ERR(dentry);
+		goto err;
+	}
+
+	dentry = securityfs_create_file("enforce", 0600, root, NULL,
+					      &enforce_fops);
+	if (IS_ERR(dentry)) {
+		rc = PTR_ERR(dentry);
+		goto err;
+	}
+
+	policy_root = securityfs_create_dir("policies", root);
+	if (IS_ERR(policy_root)) {
+		rc = PTR_ERR(policy_root);
+		goto err;
+	}
+
+	ap = rcu_access_pointer(ipe_active_policy);
+	if (ap) {
+		rc = ipe_new_policyfs_node(ap);
+		if (rc)
+			goto err;
+	}
+
+	dentry = securityfs_create_file("new_policy", 0200, root, NULL, &np_fops);
+	if (IS_ERR(dentry)) {
+		rc = PTR_ERR(dentry);
+		goto err;
+	}
+
+	return 0;
+err:
+	securityfs_remove(root);
+	return rc;
+}

linux-7.2.3/security/ipe/fs.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_FS_H
+#define _IPE_FS_H
+
+#include "policy.h"
+
+extern struct dentry *policy_root __ro_after_init;
+
+int ipe_new_policyfs_node(struct ipe_policy *p);
+void ipe_del_policyfs_node(struct ipe_policy *p);
+
+#endif /* _IPE_FS_H */

linux-7.2.3/security/ipe/hooks.c

@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/fs_struct.h>
+#include <linux/types.h>
+#include <linux/binfmts.h>
+#include <linux/mman.h>
+#include <linux/blk_types.h>
+
+#include "ipe.h"
+#include "hooks.h"
+#include "eval.h"
+#include "digest.h"
+
+/**
+ * ipe_bprm_check_security() - ipe security hook function for bprm check.
+ * @bprm: Supplies a pointer to a linux_binprm structure to source the file
+ *	  being evaluated.
+ *
+ * This LSM hook is called when a binary is loaded through the exec
+ * family of system calls.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_bprm_check_security(struct linux_binprm *bprm)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+
+	ipe_build_eval_ctx(&ctx, bprm->file, IPE_OP_EXEC, IPE_HOOK_BPRM_CHECK);
+	return ipe_evaluate_event(&ctx);
+}
+
+/**
+ * ipe_bprm_creds_for_exec() - ipe security hook function for bprm creds check.
+ * @bprm: Supplies a pointer to a linux_binprm structure to source the file
+ *	  being evaluated.
+ *
+ * This LSM hook is called when userspace signals the kernel to check a file
+ * for execution through the execveat syscall with the AT_EXECVE_CHECK flag.
+ * The hook triggers IPE policy evaluation on the script file and returns
+ * the policy decision to userspace. The userspace program receives the
+ * return code and can decide whether to proceed with script execution.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_bprm_creds_for_exec(struct linux_binprm *bprm)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+
+	if (!bprm->is_check)
+		return 0;
+
+	ipe_build_eval_ctx(&ctx, bprm->file, IPE_OP_EXEC,
+			   IPE_HOOK_BPRM_CREDS_FOR_EXEC);
+	return ipe_evaluate_event(&ctx);
+}
+
+/**
+ * ipe_mmap_file() - ipe security hook function for mmap check.
+ * @f: File being mmap'd. Can be NULL in the case of anonymous memory.
+ * @reqprot: The requested protection on the mmap, passed from usermode.
+ * @prot: The effective protection on the mmap, resolved from reqprot and
+ *	  system configuration.
+ * @flags: Unused.
+ *
+ * This hook is called when a file is loaded through the mmap
+ * family of system calls.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_mmap_file(struct file *f, unsigned long reqprot __always_unused,
+		  unsigned long prot, unsigned long flags)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+
+	if (prot & PROT_EXEC) {
+		ipe_build_eval_ctx(&ctx, f, IPE_OP_EXEC, IPE_HOOK_MMAP);
+		return ipe_evaluate_event(&ctx);
+	}
+
+	return 0;
+}
+
+/**
+ * ipe_file_mprotect() - ipe security hook function for mprotect check.
+ * @vma: Existing virtual memory area created by mmap or similar.
+ * @reqprot: The requested protection on the mmap, passed from usermode.
+ * @prot: The effective protection on the mmap, resolved from reqprot and
+ *	  system configuration.
+ *
+ * This LSM hook is called when a mmap'd region of memory is changing
+ * its protections via mprotect.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_file_mprotect(struct vm_area_struct *vma,
+		      unsigned long reqprot __always_unused,
+		      unsigned long prot)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+
+	/* Already Executable */
+	if (vma->vm_flags & VM_EXEC)
+		return 0;
+
+	if (prot & PROT_EXEC) {
+		ipe_build_eval_ctx(&ctx, vma->vm_file, IPE_OP_EXEC, IPE_HOOK_MPROTECT);
+		return ipe_evaluate_event(&ctx);
+	}
+
+	return 0;
+}
+
+/**
+ * ipe_kernel_read_file() - ipe security hook function for kernel read.
+ * @file: Supplies a pointer to the file structure being read in from disk.
+ * @id: Supplies the enumeration identifying the purpose of the read.
+ * @contents: Unused.
+ *
+ * This LSM hook is called when a file is read from disk in the kernel.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_kernel_read_file(struct file *file, enum kernel_read_file_id id,
+			 bool contents)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+	enum ipe_op_type op;
+
+	switch (id) {
+	case READING_FIRMWARE:
+		op = IPE_OP_FIRMWARE;
+		break;
+	case READING_MODULE:
+	case READING_MODULE_COMPRESSED:
+		op = IPE_OP_KERNEL_MODULE;
+		break;
+	case READING_KEXEC_INITRAMFS:
+		op = IPE_OP_KEXEC_INITRAMFS;
+		break;
+	case READING_KEXEC_IMAGE:
+		op = IPE_OP_KEXEC_IMAGE;
+		break;
+	case READING_POLICY:
+		op = IPE_OP_POLICY;
+		break;
+	case READING_X509_CERTIFICATE:
+		op = IPE_OP_X509;
+		break;
+	default:
+		op = IPE_OP_INVALID;
+		WARN(1, "no rule setup for kernel_read_file enum %d", id);
+	}
+
+	ipe_build_eval_ctx(&ctx, file, op, IPE_HOOK_KERNEL_READ);
+	return ipe_evaluate_event(&ctx);
+}
+
+/**
+ * ipe_kernel_load_data() - ipe security hook function for kernel load data.
+ * @id: Supplies the enumeration identifying the purpose of the load.
+ * @contents: Unused.
+ *
+ * This LSM hook is called when a data buffer provided by userspace is loading
+ * into the kernel.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_kernel_load_data(enum kernel_load_data_id id, bool contents)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+	enum ipe_op_type op;
+
+	switch (id) {
+	case LOADING_FIRMWARE:
+		op = IPE_OP_FIRMWARE;
+		break;
+	case LOADING_MODULE:
+		op = IPE_OP_KERNEL_MODULE;
+		break;
+	case LOADING_KEXEC_INITRAMFS:
+		op = IPE_OP_KEXEC_INITRAMFS;
+		break;
+	case LOADING_KEXEC_IMAGE:
+		op = IPE_OP_KEXEC_IMAGE;
+		break;
+	case LOADING_POLICY:
+		op = IPE_OP_POLICY;
+		break;
+	case LOADING_X509_CERTIFICATE:
+		op = IPE_OP_X509;
+		break;
+	default:
+		op = IPE_OP_INVALID;
+		WARN(1, "no rule setup for kernel_load_data enum %d", id);
+	}
+
+	ipe_build_eval_ctx(&ctx, NULL, op, IPE_HOOK_KERNEL_LOAD);
+	return ipe_evaluate_event(&ctx);
+}
+
+/**
+ * ipe_unpack_initramfs() - Mark the current rootfs as initramfs.
+ */
+void ipe_unpack_initramfs(void)
+{
+	ipe_sb(current->fs->root.mnt->mnt_sb)->initramfs = true;
+}
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+/**
+ * ipe_bdev_free_security() - Free IPE's LSM blob of block_devices.
+ * @bdev: Supplies a pointer to a block_device that contains the structure
+ *	  to free.
+ */
+void ipe_bdev_free_security(struct block_device *bdev)
+{
+	struct ipe_bdev *blob = ipe_bdev(bdev);
+
+	ipe_digest_free(blob->root_hash);
+}
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE
+static void ipe_set_dmverity_signature(struct ipe_bdev *blob,
+				       const void *value,
+				       size_t size)
+{
+	blob->dm_verity_signed = size > 0 && value;
+}
+#else
+static inline void ipe_set_dmverity_signature(struct ipe_bdev *blob,
+					      const void *value,
+					      size_t size)
+{
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */
+
+/**
+ * ipe_bdev_setintegrity() - Save integrity data from a bdev to IPE's LSM blob.
+ * @bdev: Supplies a pointer to a block_device that contains the LSM blob.
+ * @type: Supplies the integrity type.
+ * @value: Supplies the value to store.
+ * @size: The size of @value.
+ *
+ * This hook is currently used to save dm-verity's root hash or the existence
+ * of a validated signed dm-verity root hash into LSM blob.
+ *
+ * Return: %0 on success. If an error occurs, the function will return the
+ * -errno.
+ */
+int ipe_bdev_setintegrity(struct block_device *bdev, enum lsm_integrity_type type,
+			  const void *value, size_t size)
+{
+	const struct dm_verity_digest *digest = NULL;
+	struct ipe_bdev *blob = ipe_bdev(bdev);
+	struct digest_info *info = NULL;
+
+	if (type == LSM_INT_DMVERITY_SIG_VALID) {
+		ipe_set_dmverity_signature(blob, value, size);
+
+		return 0;
+	}
+
+	if (type != LSM_INT_DMVERITY_ROOTHASH)
+		return -EINVAL;
+
+	if (!value) {
+		ipe_digest_free(blob->root_hash);
+		blob->root_hash = NULL;
+
+		return 0;
+	}
+	digest = value;
+
+	info = kzalloc_obj(*info);
+	if (!info)
+		return -ENOMEM;
+
+	info->digest = kmemdup(digest->digest, digest->digest_len, GFP_KERNEL);
+	if (!info->digest)
+		goto err;
+
+	info->alg = kstrdup(digest->alg, GFP_KERNEL);
+	if (!info->alg)
+		goto err;
+
+	info->digest_len = digest->digest_len;
+
+	ipe_digest_free(blob->root_hash);
+	blob->root_hash = info;
+
+	return 0;
+err:
+	ipe_digest_free(info);
+
+	return -ENOMEM;
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+/**
+ * ipe_inode_setintegrity() - save integrity data from a inode to IPE's LSM blob.
+ * @inode: The inode to source the security blob from.
+ * @type: Supplies the integrity type.
+ * @value: The value to be stored.
+ * @size: The size of @value.
+ *
+ * This hook is currently used to save the existence of a validated fs-verity
+ * builtin signature into LSM blob.
+ *
+ * Return: %0 on success. If an error occurs, the function will return the
+ * -errno.
+ */
+int ipe_inode_setintegrity(const struct inode *inode,
+			   enum lsm_integrity_type type,
+			   const void *value, size_t size)
+{
+	struct ipe_inode *inode_sec = ipe_inode(inode);
+
+	if (type == LSM_INT_FSVERITY_BUILTINSIG_VALID) {
+		inode_sec->fs_verity_signed = size > 0 && value;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */

linux-7.2.3/security/ipe/hooks.h

@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#ifndef _IPE_HOOKS_H
+#define _IPE_HOOKS_H
+
+#include <linux/fs.h>
+#include <linux/binfmts.h>
+#include <linux/security.h>
+#include <linux/blk_types.h>
+#include <linux/fsverity.h>
+
+enum ipe_hook_type {
+	IPE_HOOK_BPRM_CHECK = 0,
+	IPE_HOOK_BPRM_CREDS_FOR_EXEC,
+	IPE_HOOK_MMAP,
+	IPE_HOOK_MPROTECT,
+	IPE_HOOK_KERNEL_READ,
+	IPE_HOOK_KERNEL_LOAD,
+	__IPE_HOOK_MAX
+};
+
+#define IPE_HOOK_INVALID __IPE_HOOK_MAX
+
+int ipe_bprm_check_security(struct linux_binprm *bprm);
+
+int ipe_bprm_creds_for_exec(struct linux_binprm *bprm);
+
+int ipe_mmap_file(struct file *f, unsigned long reqprot, unsigned long prot,
+		  unsigned long flags);
+
+int ipe_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
+		      unsigned long prot);
+
+int ipe_kernel_read_file(struct file *file, enum kernel_read_file_id id,
+			 bool contents);
+
+int ipe_kernel_load_data(enum kernel_load_data_id id, bool contents);
+
+void ipe_unpack_initramfs(void);
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+void ipe_bdev_free_security(struct block_device *bdev);
+
+int ipe_bdev_setintegrity(struct block_device *bdev, enum lsm_integrity_type type,
+			  const void *value, size_t len);
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+int ipe_inode_setintegrity(const struct inode *inode, enum lsm_integrity_type type,
+			   const void *value, size_t size);
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+#endif /* _IPE_HOOKS_H */

linux-7.2.3/security/ipe/ipe.c

@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#include <uapi/linux/lsm.h>
+
+#include "ipe.h"
+#include "eval.h"
+#include "hooks.h"
+
+extern const char *const ipe_boot_policy;
+bool ipe_enabled;
+
+static struct lsm_blob_sizes ipe_blobs __ro_after_init = {
+	.lbs_superblock = sizeof(struct ipe_superblock),
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+	.lbs_bdev = sizeof(struct ipe_bdev),
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+	.lbs_inode = sizeof(struct ipe_inode),
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+};
+
+static const struct lsm_id ipe_lsmid = {
+	.name = "ipe",
+	.id = LSM_ID_IPE,
+};
+
+struct ipe_superblock *ipe_sb(const struct super_block *sb)
+{
+	return sb->s_security + ipe_blobs.lbs_superblock;
+}
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+struct ipe_bdev *ipe_bdev(struct block_device *b)
+{
+	return b->bd_security + ipe_blobs.lbs_bdev;
+}
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+struct ipe_inode *ipe_inode(const struct inode *inode)
+{
+	return inode->i_security + ipe_blobs.lbs_inode;
+}
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+static struct security_hook_list ipe_hooks[] __ro_after_init = {
+	LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security),
+	LSM_HOOK_INIT(bprm_creds_for_exec, ipe_bprm_creds_for_exec),
+	LSM_HOOK_INIT(mmap_file, ipe_mmap_file),
+	LSM_HOOK_INIT(file_mprotect, ipe_file_mprotect),
+	LSM_HOOK_INIT(kernel_read_file, ipe_kernel_read_file),
+	LSM_HOOK_INIT(kernel_load_data, ipe_kernel_load_data),
+	LSM_HOOK_INIT(initramfs_populated, ipe_unpack_initramfs),
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+	LSM_HOOK_INIT(bdev_free_security, ipe_bdev_free_security),
+	LSM_HOOK_INIT(bdev_setintegrity, ipe_bdev_setintegrity),
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+	LSM_HOOK_INIT(inode_setintegrity, ipe_inode_setintegrity),
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+};
+
+/**
+ * ipe_init() - Entry point of IPE.
+ *
+ * This is called at LSM init, which happens occurs early during kernel
+ * start up. During this phase, IPE registers its hooks and loads the
+ * builtin boot policy.
+ *
+ * Return:
+ * * %0		- OK
+ * * %-ENOMEM	- Out of memory (OOM)
+ */
+static int __init ipe_init(void)
+{
+	struct ipe_policy *p = NULL;
+
+	security_add_hooks(ipe_hooks, ARRAY_SIZE(ipe_hooks), &ipe_lsmid);
+	ipe_enabled = true;
+
+	if (ipe_boot_policy) {
+		p = ipe_new_policy(ipe_boot_policy, strlen(ipe_boot_policy),
+				   NULL, 0);
+		if (IS_ERR(p))
+			return PTR_ERR(p);
+
+		rcu_assign_pointer(ipe_active_policy, p);
+	}
+
+	return 0;
+}
+
+DEFINE_LSM(ipe) = {
+	.id = &ipe_lsmid,
+	.init = ipe_init,
+	.blobs = &ipe_blobs,
+	.initcall_fs = ipe_init_securityfs,
+};

linux-7.2.3/security/ipe/ipe.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_H
+#define _IPE_H
+
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+#define pr_fmt(fmt) "ipe: " fmt
+
+#include <linux/lsm_hooks.h>
+struct ipe_superblock *ipe_sb(const struct super_block *sb);
+
+extern bool ipe_enabled;
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+struct ipe_bdev *ipe_bdev(struct block_device *b);
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+struct ipe_inode *ipe_inode(const struct inode *inode);
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+int ipe_init_securityfs(void);
+
+#endif /* _IPE_H */

linux-7.2.3/security/ipe/policy.c

@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/errno.h>
+#include <linux/verification.h>
+
+#include "ipe.h"
+#include "eval.h"
+#include "fs.h"
+#include "policy.h"
+#include "policy_parser.h"
+#include "audit.h"
+
+/* lock for synchronizing writers across ipe policy */
+DEFINE_MUTEX(ipe_policy_lock);
+
+/**
+ * ver_to_u64() - Convert an internal ipe_policy_version to a u64.
+ * @p: Policy to extract the version from.
+ *
+ * Bits (LSB is index 0):
+ *	[48,32] -> Major
+ *	[32,16] -> Minor
+ *	[16, 0] -> Revision
+ *
+ * Return: u64 version of the embedded version structure.
+ */
+static inline u64 ver_to_u64(const struct ipe_policy *const p)
+{
+	u64 r;
+
+	r = (((u64)p->parsed->version.major) << 32)
+	  | (((u64)p->parsed->version.minor) << 16)
+	  | ((u64)(p->parsed->version.rev));
+
+	return r;
+}
+
+/**
+ * ipe_free_policy() - Deallocate a given IPE policy.
+ * @p: Supplies the policy to free.
+ *
+ * Safe to call on IS_ERR/NULL.
+ */
+void ipe_free_policy(struct ipe_policy *p)
+{
+	if (IS_ERR_OR_NULL(p))
+		return;
+
+	ipe_del_policyfs_node(p);
+	ipe_free_parsed_policy(p->parsed);
+	/*
+	 * p->text is allocated only when p->pkcs7 is not NULL
+	 * otherwise it points to the plaintext data inside the pkcs7
+	 */
+	if (!p->pkcs7)
+		kfree(p->text);
+	kfree(p->pkcs7);
+	kfree(p);
+}
+
+static int set_pkcs7_data(void *ctx, const void *data, size_t len,
+			  size_t asn1hdrlen __always_unused)
+{
+	struct ipe_policy *p = ctx;
+
+	p->text = (const char *)data;
+	p->textlen = len;
+
+	return 0;
+}
+
+/**
+ * ipe_update_policy() - parse a new policy and replace old with it.
+ * @root: Supplies a pointer to the securityfs inode saved the policy.
+ * @text: Supplies a pointer to the plain text policy.
+ * @textlen: Supplies the length of @text.
+ * @pkcs7: Supplies a pointer to a buffer containing a pkcs7 message.
+ * @pkcs7len: Supplies the length of @pkcs7len.
+ *
+ * @text/@textlen is mutually exclusive with @pkcs7/@pkcs7len - see
+ * ipe_new_policy.
+ *
+ * Context: Requires root->i_rwsem to be held.
+ * Return:
+ * * %0	- Success
+ * * %-ENOENT	- Policy was deleted while updating
+ * * %-EINVAL	- Policy name mismatch
+ * * %-ESTALE	- Policy version too old
+ */
+int ipe_update_policy(struct inode *root, const char *text, size_t textlen,
+		      const char *pkcs7, size_t pkcs7len)
+{
+	struct ipe_policy *old, *ap, *new = NULL;
+	int rc = 0;
+
+	old = (struct ipe_policy *)root->i_private;
+	if (!old)
+		return -ENOENT;
+
+	new = ipe_new_policy(text, textlen, pkcs7, pkcs7len);
+	if (IS_ERR(new))
+		return PTR_ERR(new);
+
+	if (strcmp(new->parsed->name, old->parsed->name)) {
+		rc = -EINVAL;
+		goto err;
+	}
+
+	if (ver_to_u64(old) >= ver_to_u64(new)) {
+		rc = -ESTALE;
+		goto err;
+	}
+
+	root->i_private = new;
+	swap(new->policyfs, old->policyfs);
+	ipe_audit_policy_load(new);
+
+	mutex_lock(&ipe_policy_lock);
+	ap = rcu_dereference_protected(ipe_active_policy,
+				       lockdep_is_held(&ipe_policy_lock));
+	if (old == ap) {
+		rcu_assign_pointer(ipe_active_policy, new);
+		mutex_unlock(&ipe_policy_lock);
+		ipe_audit_policy_activation(old, new);
+	} else {
+		mutex_unlock(&ipe_policy_lock);
+	}
+	synchronize_rcu();
+	ipe_free_policy(old);
+
+	return 0;
+err:
+	ipe_free_policy(new);
+	return rc;
+}
+
+/**
+ * ipe_new_policy() - Allocate and parse an ipe_policy structure.
+ *
+ * @text: Supplies a pointer to the plain-text policy to parse.
+ * @textlen: Supplies the length of @text.
+ * @pkcs7: Supplies a pointer to a pkcs7-signed IPE policy.
+ * @pkcs7len: Supplies the length of @pkcs7.
+ *
+ * @text/@textlen Should be NULL/0 if @pkcs7/@pkcs7len is set.
+ *
+ * Return:
+ * * a pointer to the ipe_policy structure	- Success
+ * * %-EBADMSG				- Policy is invalid
+ * * %-ENOMEM				- Out of memory (OOM)
+ * * %-ERANGE				- Policy version number overflow
+ * * %-EINVAL				- Policy version parsing error
+ * * %-ENOKEY				- Policy signing key not found
+ * * %-EKEYREJECTED			- Policy signature verification failed
+ */
+struct ipe_policy *ipe_new_policy(const char *text, size_t textlen,
+				  const char *pkcs7, size_t pkcs7len)
+{
+	struct ipe_policy *new = NULL;
+	int rc = 0;
+
+	new = kzalloc_obj(*new);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+
+	if (!text) {
+		new->pkcs7len = pkcs7len;
+		new->pkcs7 = kmemdup(pkcs7, pkcs7len, GFP_KERNEL);
+		if (!new->pkcs7) {
+			rc = -ENOMEM;
+			goto err;
+		}
+
+		rc = verify_pkcs7_signature(NULL, 0, new->pkcs7, pkcs7len,
+#ifdef CONFIG_IPE_POLICY_SIG_SECONDARY_KEYRING
+					    VERIFY_USE_SECONDARY_KEYRING,
+#else
+					    NULL,
+#endif
+					    VERIFYING_UNSPECIFIED_SIGNATURE,
+					    set_pkcs7_data, new);
+#ifdef CONFIG_IPE_POLICY_SIG_PLATFORM_KEYRING
+		if (rc == -ENOKEY || rc == -EKEYREJECTED)
+			rc = verify_pkcs7_signature(NULL, 0, new->pkcs7, pkcs7len,
+						    VERIFY_USE_PLATFORM_KEYRING,
+						    VERIFYING_UNSPECIFIED_SIGNATURE,
+						    set_pkcs7_data, new);
+#endif
+		if (rc)
+			goto err;
+	} else {
+		new->textlen = textlen;
+		new->text = kstrdup(text, GFP_KERNEL);
+		if (!new->text) {
+			rc = -ENOMEM;
+			goto err;
+		}
+	}
+
+	rc = ipe_parse_policy(new);
+	if (rc)
+		goto err;
+
+	return new;
+err:
+	ipe_free_policy(new);
+	return ERR_PTR(rc);
+}
+
+/**
+ * ipe_set_active_pol() - Make @p the active policy.
+ * @p: Supplies a pointer to the policy to make active.
+ *
+ * Context: Requires root->i_rwsem, which i_private has the policy, to be held.
+ * Return:
+ * * %0	- Success
+ * * %-EINVAL	- New active policy version is invalid
+ */
+int ipe_set_active_pol(const struct ipe_policy *p)
+{
+	struct ipe_policy *ap = NULL;
+
+	mutex_lock(&ipe_policy_lock);
+
+	ap = rcu_dereference_protected(ipe_active_policy,
+				       lockdep_is_held(&ipe_policy_lock));
+	if (ap == p) {
+		mutex_unlock(&ipe_policy_lock);
+		return 0;
+	}
+	if (ap && ver_to_u64(ap) > ver_to_u64(p)) {
+		mutex_unlock(&ipe_policy_lock);
+		return -EINVAL;
+	}
+
+	rcu_assign_pointer(ipe_active_policy, p);
+	ipe_audit_policy_activation(ap, p);
+	mutex_unlock(&ipe_policy_lock);
+
+	return 0;
+}

linux-7.2.3/security/ipe/policy.h

@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#ifndef _IPE_POLICY_H
+#define _IPE_POLICY_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+
+enum ipe_op_type {
+	IPE_OP_EXEC = 0,
+	IPE_OP_FIRMWARE,
+	IPE_OP_KERNEL_MODULE,
+	IPE_OP_KEXEC_IMAGE,
+	IPE_OP_KEXEC_INITRAMFS,
+	IPE_OP_POLICY,
+	IPE_OP_X509,
+	__IPE_OP_MAX,
+};
+
+#define IPE_OP_INVALID __IPE_OP_MAX
+
+enum ipe_action_type {
+	IPE_ACTION_ALLOW = 0,
+	IPE_ACTION_DENY,
+	__IPE_ACTION_MAX
+};
+
+#define IPE_ACTION_INVALID __IPE_ACTION_MAX
+
+enum ipe_prop_type {
+	IPE_PROP_BOOT_VERIFIED_FALSE,
+	IPE_PROP_BOOT_VERIFIED_TRUE,
+	IPE_PROP_DMV_ROOTHASH,
+	IPE_PROP_DMV_SIG_FALSE,
+	IPE_PROP_DMV_SIG_TRUE,
+	IPE_PROP_FSV_DIGEST,
+	IPE_PROP_FSV_SIG_FALSE,
+	IPE_PROP_FSV_SIG_TRUE,
+	__IPE_PROP_MAX
+};
+
+#define IPE_PROP_INVALID __IPE_PROP_MAX
+
+struct ipe_prop {
+	struct list_head next;
+	enum ipe_prop_type type;
+	void *value;
+};
+
+struct ipe_rule {
+	enum ipe_op_type op;
+	enum ipe_action_type action;
+	struct list_head props;
+	struct list_head next;
+};
+
+struct ipe_op_table {
+	struct list_head rules;
+	enum ipe_action_type default_action;
+};
+
+struct ipe_parsed_policy {
+	const char *name;
+	struct {
+		u16 major;
+		u16 minor;
+		u16 rev;
+	} version;
+
+	enum ipe_action_type global_default_action;
+
+	struct ipe_op_table rules[__IPE_OP_MAX];
+};
+
+struct ipe_policy {
+	const char *pkcs7;
+	size_t pkcs7len;
+
+	const char *text;
+	size_t textlen;
+
+	struct ipe_parsed_policy *parsed;
+
+	struct dentry *policyfs;
+};
+
+struct ipe_policy *ipe_new_policy(const char *text, size_t textlen,
+				  const char *pkcs7, size_t pkcs7len);
+void ipe_free_policy(struct ipe_policy *pol);
+int ipe_update_policy(struct inode *root, const char *text, size_t textlen,
+		      const char *pkcs7, size_t pkcs7len);
+int ipe_set_active_pol(const struct ipe_policy *p);
+extern struct mutex ipe_policy_lock;
+
+#endif /* _IPE_POLICY_H */

linux-7.2.3/security/ipe/policy_fs.c

@@ -0,0 +1,490 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/types.h>
+#include <linux/dcache.h>
+#include <linux/security.h>
+
+#include "ipe.h"
+#include "policy.h"
+#include "eval.h"
+#include "fs.h"
+#include "audit.h"
+
+#define MAX_VERSION_SIZE ARRAY_SIZE("65535.65535.65535")
+
+/**
+ * struct ipefs_file - defines a file in securityfs.
+ *
+ * @name: file name inside the policy subdirectory
+ * @access: file permissions
+ * @fops: &file_operations specific to this file
+ */
+struct ipefs_file {
+	const char *name;
+	umode_t access;
+	const struct file_operations *fops;
+};
+
+/**
+ * read_pkcs7() - Read handler for "ipe/policies/$name/pkcs7".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the pkcs7 blob representing the policy
+ * on success. If the policy is unsigned (like the boot policy), this
+ * will return -ENOENT.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted or is unsigned
+ */
+static ssize_t read_pkcs7(struct file *f, char __user *data,
+			  size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	if (!p->pkcs7) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->pkcs7, p->pkcs7len);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_policy() - Read handler for "ipe/policies/$name/policy".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the plain-text version of the policy
+ * on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_policy(struct file *f, char __user *data,
+			   size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->text, p->textlen);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_name() - Read handler for "ipe/policies/$name/name".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the policy_name attribute on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_name(struct file *f, char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->parsed->name,
+				     strlen(p->parsed->name));
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_version() - Read handler for "ipe/policies/$name/version".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the version string on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_version(struct file *f, char __user *data,
+			    size_t len, loff_t *offset)
+{
+	char buffer[MAX_VERSION_SIZE] = { 0 };
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	size_t strsize = 0;
+	ssize_t rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	strsize = scnprintf(buffer, ARRAY_SIZE(buffer), "%hu.%hu.%hu",
+			    p->parsed->version.major, p->parsed->version.minor,
+			    p->parsed->version.rev);
+
+	rc = simple_read_from_buffer(data, len, offset, buffer, strsize);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * setactive() - Write handler for "ipe/policies/$name/active".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission
+ * * %-EINVAL			- Invalid input
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t setactive(struct file *f, const char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	bool value = false;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	rc = kstrtobool_from_user(data, len, &value);
+	if (rc)
+		return rc;
+
+	if (!value)
+		return -EINVAL;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = ipe_set_active_pol(p);
+
+out:
+	inode_unlock(root);
+	return (rc < 0) ? rc : len;
+}
+
+/**
+ * getactive() - Read handler for "ipe/policies/$name/active".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the 1 or 0 depending on if the
+ * corresponding policy is active.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t getactive(struct file *f, char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	const char *str;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		inode_unlock_shared(root);
+		return -ENOENT;
+	}
+	inode_unlock_shared(root);
+
+	str = (p == rcu_access_pointer(ipe_active_policy)) ? "1" : "0";
+	rc = simple_read_from_buffer(data, len, offset, str, 1);
+
+	return rc;
+}
+
+/**
+ * update_policy() - Write handler for "ipe/policies/$name/update".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * On success this updates the policy represented by $name,
+ * in-place.
+ *
+ * Return:
+ * * Length of buffer written		- Success
+ * * %-EPERM				- Insufficient permission
+ * * %-ENOMEM				- Out of memory (OOM)
+ * * %-ENOENT				- Policy was deleted while updating
+ * * %-EINVAL				- Policy name mismatch
+ * * %-ESTALE				- Policy version too old
+ */
+static ssize_t update_policy(struct file *f, const char __user *data,
+			     size_t len, loff_t *offset)
+{
+	struct inode *root = NULL;
+	char *copy = NULL;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) {
+		rc = -EPERM;
+		goto out;
+	}
+
+	copy = memdup_user(data, len);
+	if (IS_ERR(copy)) {
+		rc = PTR_ERR(copy);
+		copy = NULL;
+		goto out;
+	}
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+	rc = ipe_update_policy(root, NULL, 0, copy, len);
+	inode_unlock(root);
+
+out:
+	kfree(copy);
+	if (rc) {
+		ipe_audit_policy_load(ERR_PTR(rc));
+		return rc;
+	}
+
+	return len;
+}
+
+/**
+ * delete_policy() - write handler for  "ipe/policies/$name/delete".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * On success this deletes the policy represented by $name.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission/deleting active policy
+ * * %-EINVAL			- Invalid input
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t delete_policy(struct file *f, const char __user *data,
+			     size_t len, loff_t *offset)
+{
+	struct ipe_policy *ap = NULL;
+	struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	bool value = false;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	rc = kstrtobool_from_user(data, len, &value);
+	if (rc)
+		return rc;
+
+	if (!value)
+		return -EINVAL;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		inode_unlock(root);
+		return -ENOENT;
+	}
+
+	mutex_lock(&ipe_policy_lock);
+	ap = rcu_dereference_protected(ipe_active_policy,
+				       lockdep_is_held(&ipe_policy_lock));
+	if (p == ap) {
+		mutex_unlock(&ipe_policy_lock);
+		inode_unlock(root);
+		return -EPERM;
+	}
+	mutex_unlock(&ipe_policy_lock);
+
+	root->i_private = NULL;
+	inode_unlock(root);
+
+	synchronize_rcu();
+	ipe_free_policy(p);
+
+	return len;
+}
+
+static const struct file_operations content_fops = {
+	.read = read_policy,
+};
+
+static const struct file_operations pkcs7_fops = {
+	.read = read_pkcs7,
+};
+
+static const struct file_operations name_fops = {
+	.read = read_name,
+};
+
+static const struct file_operations ver_fops = {
+	.read = read_version,
+};
+
+static const struct file_operations active_fops = {
+	.write = setactive,
+	.read = getactive,
+};
+
+static const struct file_operations update_fops = {
+	.write = update_policy,
+};
+
+static const struct file_operations delete_fops = {
+	.write = delete_policy,
+};
+
+/*
+ * policy_subdir - files under a policy subdirectory
+ */
+static const struct ipefs_file policy_subdir[] = {
+	{ "pkcs7", 0444, &pkcs7_fops },
+	{ "policy", 0444, &content_fops },
+	{ "name", 0444, &name_fops },
+	{ "version", 0444, &ver_fops },
+	{ "active", 0600, &active_fops },
+	{ "update", 0200, &update_fops },
+	{ "delete", 0200, &delete_fops },
+};
+
+/**
+ * ipe_del_policyfs_node() - Delete a securityfs entry for @p.
+ * @p: Supplies a pointer to the policy to delete a securityfs entry for.
+ */
+void ipe_del_policyfs_node(struct ipe_policy *p)
+{
+	securityfs_remove(p->policyfs);
+	p->policyfs = NULL;
+}
+
+/**
+ * ipe_new_policyfs_node() - Create a securityfs entry for @p.
+ * @p: Supplies a pointer to the policy to create a securityfs entry for.
+ *
+ * Return: %0 on success. If an error occurs, the function will return
+ * the -errno.
+ */
+int ipe_new_policyfs_node(struct ipe_policy *p)
+{
+	const struct ipefs_file *f = NULL;
+	struct dentry *policyfs = NULL;
+	struct inode *root = NULL;
+	struct dentry *d = NULL;
+	size_t i = 0;
+	int rc = 0;
+
+	if (p->policyfs)
+		return 0;
+
+	policyfs = securityfs_create_dir(p->parsed->name, policy_root);
+	if (IS_ERR(policyfs))
+		return PTR_ERR(policyfs);
+
+	root = d_inode(policyfs);
+
+	for (i = 0; i < ARRAY_SIZE(policy_subdir); ++i) {
+		f = &policy_subdir[i];
+
+		d = securityfs_create_file(f->name, f->access, policyfs,
+					   NULL, f->fops);
+		if (IS_ERR(d)) {
+			rc = PTR_ERR(d);
+			goto err;
+		}
+	}
+
+	inode_lock(root);
+	p->policyfs = policyfs;
+	root->i_private = p;
+	inode_unlock(root);
+
+	return 0;
+err:
+	securityfs_remove(policyfs);
+	return rc;
+}

linux-7.2.3/security/ipe/policy_parser.c

@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/parser.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+
+#include "policy.h"
+#include "policy_parser.h"
+#include "digest.h"
+
+#define START_COMMENT	'#'
+#define IPE_POLICY_DELIM " \t"
+#define IPE_LINE_DELIM "\n\r"
+
+/**
+ * new_parsed_policy() - Allocate and initialize a parsed policy.
+ *
+ * Return:
+ * * a pointer to the ipe_parsed_policy structure	- Success
+ * * %-ENOMEM						- Out of memory (OOM)
+ */
+static struct ipe_parsed_policy *new_parsed_policy(void)
+{
+	struct ipe_parsed_policy *p = NULL;
+	struct ipe_op_table *t = NULL;
+	size_t i = 0;
+
+	p = kzalloc_obj(*p);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+
+	p->global_default_action = IPE_ACTION_INVALID;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i) {
+		t = &p->rules[i];
+
+		t->default_action = IPE_ACTION_INVALID;
+		INIT_LIST_HEAD(&t->rules);
+	}
+
+	return p;
+}
+
+/**
+ * remove_comment() - Truncate all chars following START_COMMENT in a string.
+ *
+ * @line: Supplies a policy line string for preprocessing.
+ */
+static void remove_comment(char *line)
+{
+	line = strchr(line, START_COMMENT);
+
+	if (line)
+		*line = '\0';
+}
+
+/**
+ * remove_trailing_spaces() - Truncate all trailing spaces in a string.
+ *
+ * @line: Supplies a policy line string for preprocessing.
+ *
+ * Return: The length of truncated string.
+ */
+static size_t remove_trailing_spaces(char *line)
+{
+	size_t i = 0;
+
+	i = strlen(line);
+	while (i > 0 && isspace(line[i - 1]))
+		i--;
+
+	line[i] = '\0';
+
+	return i;
+}
+
+/**
+ * parse_version() - Parse policy version.
+ * @ver: Supplies a version string to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Version string is invalid
+ * * %-ERANGE	- Version number overflow
+ * * %-EINVAL	- Parsing error
+ */
+static int parse_version(char *ver, struct ipe_parsed_policy *p)
+{
+	u16 *const cv[] = { &p->version.major, &p->version.minor, &p->version.rev };
+	size_t sep_count = 0;
+	char *token;
+	int rc = 0;
+
+	while ((token = strsep(&ver, ".")) != NULL) {
+		/* prevent overflow */
+		if (sep_count >= ARRAY_SIZE(cv))
+			return -EBADMSG;
+
+		rc = kstrtou16(token, 10, cv[sep_count]);
+		if (rc)
+			return rc;
+
+		++sep_count;
+	}
+
+	/* prevent underflow */
+	if (sep_count != ARRAY_SIZE(cv))
+		return -EBADMSG;
+
+	return 0;
+}
+
+enum header_opt {
+	IPE_HEADER_POLICY_NAME = 0,
+	IPE_HEADER_POLICY_VERSION,
+	__IPE_HEADER_MAX
+};
+
+static const match_table_t header_tokens = {
+	{IPE_HEADER_POLICY_NAME,	"policy_name=%s"},
+	{IPE_HEADER_POLICY_VERSION,	"policy_version=%s"},
+	{__IPE_HEADER_MAX,		NULL}
+};
+
+/**
+ * parse_header() - Parse policy header information.
+ * @line: Supplies header line to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Header string is invalid
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-ERANGE	- Version number overflow
+ * * %-EINVAL	- Version parsing error
+ */
+static int parse_header(char *line, struct ipe_parsed_policy *p)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *t, *ver = NULL;
+	size_t idx = 0;
+	int rc = 0;
+
+	while ((t = strsep(&line, IPE_POLICY_DELIM)) != NULL) {
+		int token;
+
+		if (*t == '\0')
+			continue;
+		if (idx >= __IPE_HEADER_MAX) {
+			rc = -EBADMSG;
+			goto out;
+		}
+
+		token = match_token(t, header_tokens, args);
+		if (token != idx) {
+			rc = -EBADMSG;
+			goto out;
+		}
+
+		switch (token) {
+		case IPE_HEADER_POLICY_NAME:
+			p->name = match_strdup(&args[0]);
+			if (!p->name)
+				rc = -ENOMEM;
+			break;
+		case IPE_HEADER_POLICY_VERSION:
+			ver = match_strdup(&args[0]);
+			if (!ver) {
+				rc = -ENOMEM;
+				break;
+			}
+			rc = parse_version(ver, p);
+			break;
+		default:
+			rc = -EBADMSG;
+		}
+		if (rc)
+			goto out;
+		++idx;
+	}
+
+	if (idx != __IPE_HEADER_MAX)
+		rc = -EBADMSG;
+
+out:
+	kfree(ver);
+	return rc;
+}
+
+/**
+ * token_default() - Determine if the given token is "DEFAULT".
+ * @token: Supplies the token string to be compared.
+ *
+ * Return:
+ * * %false	- The token is not "DEFAULT"
+ * * %true	- The token is "DEFAULT"
+ */
+static bool token_default(char *token)
+{
+	return !strcmp(token, "DEFAULT");
+}
+
+/**
+ * free_rule() - Free the supplied ipe_rule struct.
+ * @r: Supplies the ipe_rule struct to be freed.
+ *
+ * Free a ipe_rule struct @r. Note @r must be removed from any lists before
+ * calling this function.
+ */
+static void free_rule(struct ipe_rule *r)
+{
+	struct ipe_prop *p, *t;
+
+	if (IS_ERR_OR_NULL(r))
+		return;
+
+	list_for_each_entry_safe(p, t, &r->props, next) {
+		list_del(&p->next);
+		ipe_digest_free(p->value);
+		kfree(p);
+	}
+
+	kfree(r);
+}
+
+static const match_table_t operation_tokens = {
+	{IPE_OP_EXEC,			"op=EXECUTE"},
+	{IPE_OP_FIRMWARE,		"op=FIRMWARE"},
+	{IPE_OP_KERNEL_MODULE,		"op=KMODULE"},
+	{IPE_OP_KEXEC_IMAGE,		"op=KEXEC_IMAGE"},
+	{IPE_OP_KEXEC_INITRAMFS,	"op=KEXEC_INITRAMFS"},
+	{IPE_OP_POLICY,			"op=POLICY"},
+	{IPE_OP_X509,			"op=X509_CERT"},
+	{IPE_OP_INVALID,		NULL}
+};
+
+/**
+ * parse_operation() - Parse the operation type given a token string.
+ * @t: Supplies the token string to be parsed.
+ *
+ * Return: The parsed operation type.
+ */
+static enum ipe_op_type parse_operation(char *t)
+{
+	substring_t args[MAX_OPT_ARGS];
+
+	return match_token(t, operation_tokens, args);
+}
+
+static const match_table_t action_tokens = {
+	{IPE_ACTION_ALLOW,	"action=ALLOW"},
+	{IPE_ACTION_DENY,	"action=DENY"},
+	{IPE_ACTION_INVALID,	NULL}
+};
+
+/**
+ * parse_action() - Parse the action type given a token string.
+ * @t: Supplies the token string to be parsed.
+ *
+ * Return: The parsed action type.
+ */
+static enum ipe_action_type parse_action(char *t)
+{
+	substring_t args[MAX_OPT_ARGS];
+
+	return match_token(t, action_tokens, args);
+}
+
+static const match_table_t property_tokens = {
+	{IPE_PROP_BOOT_VERIFIED_FALSE,	"boot_verified=FALSE"},
+	{IPE_PROP_BOOT_VERIFIED_TRUE,	"boot_verified=TRUE"},
+	{IPE_PROP_DMV_ROOTHASH,		"dmverity_roothash=%s"},
+	{IPE_PROP_DMV_SIG_FALSE,	"dmverity_signature=FALSE"},
+	{IPE_PROP_DMV_SIG_TRUE,		"dmverity_signature=TRUE"},
+	{IPE_PROP_FSV_DIGEST,		"fsverity_digest=%s"},
+	{IPE_PROP_FSV_SIG_FALSE,	"fsverity_signature=FALSE"},
+	{IPE_PROP_FSV_SIG_TRUE,		"fsverity_signature=TRUE"},
+	{IPE_PROP_INVALID,		NULL}
+};
+
+/**
+ * parse_property() - Parse a rule property given a token string.
+ * @t: Supplies the token string to be parsed.
+ * @r: Supplies the ipe_rule the parsed property will be associated with.
+ *
+ * This function parses and associates a property with an IPE rule based
+ * on a token string.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-EBADMSG	- The supplied token cannot be parsed
+ */
+static int parse_property(char *t, struct ipe_rule *r)
+{
+	substring_t args[MAX_OPT_ARGS];
+	struct ipe_prop *p = NULL;
+	int rc = 0;
+	int token;
+	char *dup = NULL;
+
+	p = kzalloc_obj(*p);
+	if (!p)
+		return -ENOMEM;
+
+	token = match_token(t, property_tokens, args);
+
+	switch (token) {
+	case IPE_PROP_DMV_ROOTHASH:
+	case IPE_PROP_FSV_DIGEST:
+		dup = match_strdup(&args[0]);
+		if (!dup) {
+			rc = -ENOMEM;
+			goto err;
+		}
+		p->value = ipe_digest_parse(dup);
+		if (IS_ERR(p->value)) {
+			rc = PTR_ERR(p->value);
+			goto err;
+		}
+		fallthrough;
+	case IPE_PROP_BOOT_VERIFIED_FALSE:
+	case IPE_PROP_BOOT_VERIFIED_TRUE:
+	case IPE_PROP_DMV_SIG_FALSE:
+	case IPE_PROP_DMV_SIG_TRUE:
+	case IPE_PROP_FSV_SIG_FALSE:
+	case IPE_PROP_FSV_SIG_TRUE:
+		p->type = token;
+		break;
+	default:
+		rc = -EBADMSG;
+		break;
+	}
+	if (rc)
+		goto err;
+	list_add_tail(&p->next, &r->props);
+
+out:
+	kfree(dup);
+	return rc;
+err:
+	kfree(p);
+	goto out;
+}
+
+/**
+ * parse_rule() - parse a policy rule line.
+ * @line: Supplies rule line to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * 0		- Success
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-EBADMSG	- Policy syntax error
+ */
+static int parse_rule(char *line, struct ipe_parsed_policy *p)
+{
+	enum ipe_action_type action = IPE_ACTION_INVALID;
+	enum ipe_op_type op = IPE_OP_INVALID;
+	bool is_default_rule = false;
+	struct ipe_rule *r = NULL;
+	bool first_token = true;
+	bool op_parsed = false;
+	int rc = 0;
+	char *t;
+
+	if (IS_ERR_OR_NULL(line))
+		return -EBADMSG;
+
+	r = kzalloc_obj(*r);
+	if (!r)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&r->next);
+	INIT_LIST_HEAD(&r->props);
+
+	while (t = strsep(&line, IPE_POLICY_DELIM), line) {
+		if (*t == '\0')
+			continue;
+		if (first_token && token_default(t)) {
+			is_default_rule = true;
+		} else {
+			if (!op_parsed) {
+				op = parse_operation(t);
+				if (op == IPE_OP_INVALID)
+					rc = -EBADMSG;
+				else
+					op_parsed = true;
+			} else {
+				rc = parse_property(t, r);
+			}
+		}
+
+		if (rc)
+			goto err;
+		first_token = false;
+	}
+
+	action = parse_action(t);
+	if (action == IPE_ACTION_INVALID) {
+		rc = -EBADMSG;
+		goto err;
+	}
+
+	if (is_default_rule) {
+		if (!list_empty(&r->props)) {
+			rc = -EBADMSG;
+		} else if (op == IPE_OP_INVALID) {
+			if (p->global_default_action != IPE_ACTION_INVALID)
+				rc = -EBADMSG;
+			else
+				p->global_default_action = action;
+		} else {
+			if (p->rules[op].default_action != IPE_ACTION_INVALID)
+				rc = -EBADMSG;
+			else
+				p->rules[op].default_action = action;
+		}
+	} else if (op != IPE_OP_INVALID && action != IPE_ACTION_INVALID) {
+		r->op = op;
+		r->action = action;
+	} else {
+		rc = -EBADMSG;
+	}
+
+	if (rc)
+		goto err;
+	if (!is_default_rule)
+		list_add_tail(&r->next, &p->rules[op].rules);
+	else
+		free_rule(r);
+
+	return rc;
+err:
+	free_rule(r);
+	return rc;
+}
+
+/**
+ * ipe_free_parsed_policy() - free a parsed policy structure.
+ * @p: Supplies the parsed policy.
+ */
+void ipe_free_parsed_policy(struct ipe_parsed_policy *p)
+{
+	struct ipe_rule *pp, *t;
+	size_t i = 0;
+
+	if (IS_ERR_OR_NULL(p))
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i)
+		list_for_each_entry_safe(pp, t, &p->rules[i].rules, next) {
+			list_del(&pp->next);
+			free_rule(pp);
+		}
+
+	kfree(p->name);
+	kfree(p);
+}
+
+/**
+ * validate_policy() - validate a parsed policy.
+ * @p: Supplies the fully parsed policy.
+ *
+ * Given a policy structure that was just parsed, validate that all
+ * operations have their default rules or a global default rule is set.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Policy is invalid
+ */
+static int validate_policy(const struct ipe_parsed_policy *p)
+{
+	size_t i = 0;
+
+	if (p->global_default_action != IPE_ACTION_INVALID)
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i) {
+		if (p->rules[i].default_action == IPE_ACTION_INVALID)
+			return -EBADMSG;
+	}
+
+	return 0;
+}
+
+/**
+ * ipe_parse_policy() - Given a string, parse the string into an IPE policy.
+ * @p: partially filled ipe_policy structure to populate with the result.
+ *     it must have text and textlen set.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Policy is invalid
+ * * %-ENOMEM	- Out of Memory
+ * * %-ERANGE	- Policy version number overflow
+ * * %-EINVAL	- Policy version parsing error
+ */
+int ipe_parse_policy(struct ipe_policy *p)
+{
+	struct ipe_parsed_policy *pp = NULL;
+	char *policy = NULL, *dup = NULL;
+	bool header_parsed = false;
+	char *line = NULL;
+	size_t len;
+	int rc = 0;
+
+	if (!p->textlen)
+		return -EBADMSG;
+
+	policy = kmemdup_nul(p->text, p->textlen, GFP_KERNEL);
+	if (!policy)
+		return -ENOMEM;
+	dup = policy;
+
+	pp = new_parsed_policy();
+	if (IS_ERR(pp)) {
+		rc = PTR_ERR(pp);
+		goto out;
+	}
+
+	while ((line = strsep(&policy, IPE_LINE_DELIM)) != NULL) {
+		remove_comment(line);
+		len = remove_trailing_spaces(line);
+		if (!len)
+			continue;
+
+		if (!header_parsed) {
+			rc = parse_header(line, pp);
+			if (rc)
+				goto err;
+			header_parsed = true;
+		} else {
+			rc = parse_rule(line, pp);
+			if (rc)
+				goto err;
+		}
+	}
+
+	if (!header_parsed || validate_policy(pp)) {
+		rc = -EBADMSG;
+		goto err;
+	}
+
+	p->parsed = pp;
+
+out:
+	kfree(dup);
+	return rc;
+err:
+	ipe_free_parsed_policy(pp);
+	goto out;
+}

linux-7.2.3/security/ipe/policy_parser.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#ifndef _IPE_POLICY_PARSER_H
+#define _IPE_POLICY_PARSER_H
+
+int ipe_parse_policy(struct ipe_policy *p);
+void ipe_free_parsed_policy(struct ipe_parsed_policy *p);
+
+#endif /* _IPE_POLICY_PARSER_H */

linux-7.2.3/security/ipe/policy_tests.c

@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <kunit/test.h>
+#include "policy.h"
+struct policy_case {
+	const char *const policy;
+	int errno;
+	const char *const desc;
+};
+
+static const struct policy_case policy_cases[] = {
+	{
+		"policy_name=allowall policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"basic",
+	},
+	{
+		"policy_name=trailing_comment policy_version=152.0.0 #This is comment\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"trailing comment",
+	},
+	{
+		"policy_name=allowallnewline policy_version=0.2.0\n"
+		"DEFAULT action=ALLOW\n"
+		"\n",
+		0,
+		"trailing newline",
+	},
+	{
+		"policy_name=carriagereturnlinefeed policy_version=0.0.1\n"
+		"DEFAULT action=ALLOW\n"
+		"\r\n",
+		0,
+		"clrf newline",
+	},
+	{
+		"policy_name=whitespace policy_version=0.0.0\n"
+		"DEFAULT\taction=ALLOW\n"
+		"     \t     DEFAULT \t    op=EXECUTE      action=DENY\n"
+		"op=EXECUTE boot_verified=TRUE action=ALLOW\n"
+		"# this is a\tcomment\t\t\t\t\n"
+		"DEFAULT \t op=KMODULE\t\t\t  action=DENY\r\n"
+		"op=KMODULE boot_verified=TRUE action=ALLOW\n",
+		0,
+		"various whitespaces and nested default",
+	},
+	{
+		"policy_name=boot_verified policy_version=-1236.0.0\n"
+		"DEFAULT\taction=ALLOW\n",
+		-EINVAL,
+		"negative version",
+	},
+	{
+		"policy_name=$@!*&^%%\\:;{}() policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"special characters",
+	},
+	{
+		"policy_name=test policy_version=999999.0.0\n"
+		"DEFAULT action=ALLOW",
+		-ERANGE,
+		"overflow version",
+	},
+	{
+		"policy_name=test policy_version=255.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"incomplete version",
+	},
+	{
+		"policy_name=test policy_version=111.0.0.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"extra version",
+	},
+	{
+		"",
+		-EBADMSG,
+		"0-length policy",
+	},
+	{
+		"policy_name=test\0policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"random null in header",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"\0DEFAULT action=ALLOW",
+		-EBADMSG,
+		"incomplete policy from NULL",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=DENY\n\0"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW\n",
+		0,
+		"NULL truncates policy",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=abc action=ALLOW",
+		-EBADMSG,
+		"invalid property type",
+	},
+	{
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"missing policy header",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n",
+		-EBADMSG,
+		"missing default definition",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"dmverity_signature=TRUE op=EXECUTE action=ALLOW",
+		-EBADMSG,
+		"invalid rule ordering"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"action=ALLOW op=EXECUTE dmverity_signature=TRUE",
+		-EBADMSG,
+		"invalid rule ordering (2)",
+	},
+	{
+		"policy_name=test policy_version=0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW",
+		-EBADMSG,
+		"invalid version",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=UNKNOWN dmverity_signature=TRUE action=ALLOW",
+		-EBADMSG,
+		"unknown operation",
+	},
+	{
+		"policy_name=asdvpolicy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n",
+		-EBADMSG,
+		"missing space after policy name",
+	},
+	{
+		"policy_name=test\xFF\xEF policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW",
+		0,
+		"expanded ascii",
+	},
+	{
+		"policy_name=test\xFF\xEF policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_roothash=GOOD_DOG action=ALLOW",
+		-EBADMSG,
+		"invalid property value (2)",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"policy_name=test policy_version=0.1.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"double header"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT action=ALLOW\n",
+		-EBADMSG,
+		"double default"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action=DENY\n"
+		"DEFAULT op=EXECUTE action=ALLOW\n",
+		-EBADMSG,
+		"double operation default"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action=DEN\n",
+		-EBADMSG,
+		"invalid action value"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action\n",
+		-EBADMSG,
+		"invalid action value (2)"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"UNKNOWN value=true\n",
+		-EBADMSG,
+		"unrecognized statement"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_roothash=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n",
+		-EBADMSG,
+		"old-style digest"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE fsverity_digest=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n",
+		-EBADMSG,
+		"old-style digest"
+	}
+};
+
+static void pol_to_desc(const struct policy_case *c, char *desc)
+{
+	strscpy(desc, c->desc, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(ipe_policies, policy_cases, pol_to_desc);
+
+/**
+ * ipe_parser_unsigned_test - Test the parser by passing unsigned policies.
+ * @test: Supplies a pointer to a kunit structure.
+ *
+ * This is called by the kunit harness. This test does not check the correctness
+ * of the policy, but ensures that errors are handled correctly.
+ */
+static void ipe_parser_unsigned_test(struct kunit *test)
+{
+	const struct policy_case *p = test->param_value;
+	struct ipe_policy *pol;
+
+	pol = ipe_new_policy(p->policy, strlen(p->policy), NULL, 0);
+
+	if (p->errno) {
+		KUNIT_EXPECT_EQ(test, PTR_ERR(pol), p->errno);
+		return;
+	}
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pol);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pol->parsed);
+	KUNIT_EXPECT_STREQ(test, pol->text, p->policy);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, pol->pkcs7);
+	KUNIT_EXPECT_EQ(test, 0, pol->pkcs7len);
+
+	ipe_free_policy(pol);
+}
+
+/**
+ * ipe_parser_widestring_test - Ensure parser fail on a wide string policy.
+ * @test: Supplies a pointer to a kunit structure.
+ *
+ * This is called by the kunit harness.
+ */
+static void ipe_parser_widestring_test(struct kunit *test)
+{
+	const unsigned short policy[] = L"policy_name=Test policy_version=0.0.0\n"
+					L"DEFAULT action=ALLOW";
+	struct ipe_policy *pol = NULL;
+
+	pol = ipe_new_policy((const char *)policy, (ARRAY_SIZE(policy) - 1) * 2, NULL, 0);
+	KUNIT_EXPECT_TRUE(test, IS_ERR_OR_NULL(pol));
+
+	ipe_free_policy(pol);
+}
+
+static struct kunit_case ipe_parser_test_cases[] = {
+	KUNIT_CASE_PARAM(ipe_parser_unsigned_test, ipe_policies_gen_params),
+	KUNIT_CASE(ipe_parser_widestring_test),
+	{ }
+};
+
+static struct kunit_suite ipe_parser_test_suite = {
+	.name = "ipe-parser",
+	.test_cases = ipe_parser_test_cases,
+};
+
+kunit_test_suite(ipe_parser_test_suite);