@@ -7,6 +7,7 @@
obj-$(CONFIG_SECURITY_IPE) += \
eval.o \
+ hooks.o \
ipe.o \
policy.o \
policy_parser.o \
@@ -16,6 +16,20 @@
struct ipe_policy __rcu *ipe_active_policy;
+/**
+ * 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.
+ */
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+ const struct file *file,
+ enum ipe_op_type op)
+{
+ ctx->file = file;
+ ctx->op = op;
+}
+
/**
* evaluate_property() - Analyze @ctx against a rule property.
* @ctx: Supplies a pointer to the context to be evaluated.
@@ -11,6 +11,8 @@
#include "policy.h"
+#define IPE_EVAL_CTX_INIT ((struct ipe_eval_ctx){ 0 })
+
extern struct ipe_policy __rcu *ipe_active_policy;
struct ipe_eval_ctx {
@@ -19,6 +21,9 @@ struct ipe_eval_ctx {
const struct file *file;
};
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+ const struct file *file,
+ enum ipe_op_type op);
int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx);
#endif /* _IPE_EVAL_H */
new file mode 100644
@@ -0,0 +1,184 @@
+// 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/binfmts.h>
+#include <linux/mman.h>
+
+#include "ipe.h"
+#include "hooks.h"
+#include "eval.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);
+ 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);
+ 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);
+ 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:
+ 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);
+ 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);
+ return ipe_evaluate_event(&ctx);
+}
new file mode 100644
@@ -0,0 +1,25 @@
+/* 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>
+
+int ipe_bprm_check_security(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);
+
+#endif /* _IPE_HOOKS_H */
@@ -5,6 +5,7 @@
#include <uapi/linux/lsm.h>
#include "ipe.h"
+#include "hooks.h"
static struct lsm_blob_sizes ipe_blobs __ro_after_init = {
};
@@ -15,6 +16,11 @@ static const struct lsm_id ipe_lsmid = {
};
static struct security_hook_list ipe_hooks[] __ro_after_init = {
+ LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security),
+ 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),
};
/**