1 files changed, 0 insertions, 339 deletions
diff --git a/drivers/misc/lkdtm_usercopy.c b/drivers/misc/lkdtm_usercopy.c
deleted file mode 100644
index 9725aed305bb..000000000000
--- a/drivers/misc/lkdtm_usercopy.c
+++ /dev/null
@@ -1,339 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This is for all the tests related to copy_to_user() and copy_from_user()
- * hardening.
- */
-#include "lkdtm.h"
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/sched/task_stack.h>
-#include <linux/mman.h>
-#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-
-/*
- * Many of the tests here end up using const sizes, but those would
- * normally be ignored by hardened usercopy, so force the compiler
- * into choosing the non-const path to make sure we trigger the
- * hardened usercopy checks by added "unconst" to all the const copies,
- * and making sure "cache_size" isn't optimized into a const.
- */
-static volatile size_t unconst = 0;
-static volatile size_t cache_size = 1024;
-static struct kmem_cache *whitelist_cache;
-
-static const unsigned char test_text[] = "This is a test.\n";
-
-/*
- * Instead of adding -Wno-return-local-addr, just pass the stack address
- * through a function to obfuscate it from the compiler.
- */
-static noinline unsigned char *trick_compiler(unsigned char *stack)
-{
-	return stack + 0;
-}
-
-static noinline unsigned char *do_usercopy_stack_callee(int value)
-{
-	unsigned char buf[32];
-	int i;
-
-	/* Exercise stack to avoid everything living in registers. */
-	for (i = 0; i < sizeof(buf); i++) {
-		buf[i] = value & 0xff;
-	}
-
-	return trick_compiler(buf);
-}
-
-static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
-{
-	unsigned long user_addr;
-	unsigned char good_stack[32];
-	unsigned char *bad_stack;
-	int i;
-
-	/* Exercise stack to avoid everything living in registers. */
-	for (i = 0; i < sizeof(good_stack); i++)
-		good_stack[i] = test_text[i % sizeof(test_text)];
-
-	/* This is a pointer to outside our current stack frame. */
-	if (bad_frame) {
-		bad_stack = do_usercopy_stack_callee((uintptr_t)&bad_stack);
-	} else {
-		/* Put start address just inside stack. */
-		bad_stack = task_stack_page(current) + THREAD_SIZE;
-		bad_stack -= sizeof(unsigned long);
-	}
-
-	user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
-			    PROT_READ | PROT_WRITE | PROT_EXEC,
-			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
-	if (user_addr >= TASK_SIZE) {
-		pr_warn("Failed to allocate user memory\n");
-		return;
-	}
-
-	if (to_user) {
-		pr_info("attempting good copy_to_user of local stack\n");
-		if (copy_to_user((void __user *)user_addr, good_stack,
-				 unconst + sizeof(good_stack))) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user of distant stack\n");
-		if (copy_to_user((void __user *)user_addr, bad_stack,
-				 unconst + sizeof(good_stack))) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		/*
-		 * There isn't a safe way to not be protected by usercopy
-		 * if we're going to write to another thread's stack.
-		 */
-		if (!bad_frame)
-			goto free_user;
-
-		pr_info("attempting good copy_from_user of local stack\n");
-		if (copy_from_user(good_stack, (void __user *)user_addr,
-				   unconst + sizeof(good_stack))) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_from_user of distant stack\n");
-		if (copy_from_user(bad_stack, (void __user *)user_addr,
-				   unconst + sizeof(good_stack))) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-}
-
-/*
- * This checks for whole-object size validation with hardened usercopy,
- * with or without usercopy whitelisting.
- */
-static void do_usercopy_heap_size(bool to_user)
-{
-	unsigned long user_addr;
-	unsigned char *one, *two;
-	void __user *test_user_addr;
-	void *test_kern_addr;
-	size_t size = unconst + 1024;
-
-	one = kmalloc(size, GFP_KERNEL);
-	two = kmalloc(size, GFP_KERNEL);
-	if (!one || !two) {
-		pr_warn("Failed to allocate kernel memory\n");
-		goto free_kernel;
-	}
-
-	user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
-			    PROT_READ | PROT_WRITE | PROT_EXEC,
-			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
-	if (user_addr >= TASK_SIZE) {
-		pr_warn("Failed to allocate user memory\n");
-		goto free_kernel;
-	}
-
-	memset(one, 'A', size);
-	memset(two, 'B', size);
-
-	test_user_addr = (void __user *)(user_addr + 16);
-	test_kern_addr = one + 16;
-
-	if (to_user) {
-		pr_info("attempting good copy_to_user of correct size\n");
-		if (copy_to_user(test_user_addr, test_kern_addr, size / 2)) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user of too large size\n");
-		if (copy_to_user(test_user_addr, test_kern_addr, size)) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		pr_info("attempting good copy_from_user of correct size\n");
-		if (copy_from_user(test_kern_addr, test_user_addr, size / 2)) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_from_user of too large size\n");
-		if (copy_from_user(test_kern_addr, test_user_addr, size)) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-free_kernel:
-	kfree(one);
-	kfree(two);
-}
-
-/*
- * This checks for the specific whitelist window within an object. If this
- * test passes, then do_usercopy_heap_size() tests will pass too.
- */
-static void do_usercopy_heap_whitelist(bool to_user)
-{
-	unsigned long user_alloc;
-	unsigned char *buf = NULL;
-	unsigned char __user *user_addr;
-	size_t offset, size;
-
-	/* Make sure cache was prepared. */
-	if (!whitelist_cache) {
-		pr_warn("Failed to allocate kernel cache\n");
-		return;
-	}
-
-	/*
-	 * Allocate a buffer with a whitelisted window in the buffer.
-	 */
-	buf = kmem_cache_alloc(whitelist_cache, GFP_KERNEL);
-	if (!buf) {
-		pr_warn("Failed to allocate buffer from whitelist cache\n");
-		goto free_alloc;
-	}
-
-	/* Allocate user memory we'll poke at. */
-	user_alloc = vm_mmap(NULL, 0, PAGE_SIZE,
-			    PROT_READ | PROT_WRITE | PROT_EXEC,
-			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
-	if (user_alloc >= TASK_SIZE) {
-		pr_warn("Failed to allocate user memory\n");
-		goto free_alloc;
-	}
-	user_addr = (void __user *)user_alloc;
-
-	memset(buf, 'B', cache_size);
-
-	/* Whitelisted window in buffer, from kmem_cache_create_usercopy. */
-	offset = (cache_size / 4) + unconst;
-	size = (cache_size / 16) + unconst;
-
-	if (to_user) {
-		pr_info("attempting good copy_to_user inside whitelist\n");
-		if (copy_to_user(user_addr, buf + offset, size)) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user outside whitelist\n");
-		if (copy_to_user(user_addr, buf + offset - 1, size)) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		pr_info("attempting good copy_from_user inside whitelist\n");
-		if (copy_from_user(buf + offset, user_addr, size)) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_from_user outside whitelist\n");
-		if (copy_from_user(buf + offset - 1, user_addr, size)) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_alloc, PAGE_SIZE);
-free_alloc:
-	if (buf)
-		kmem_cache_free(whitelist_cache, buf);
-}
-
-/* Callable tests. */
-void lkdtm_USERCOPY_HEAP_SIZE_TO(void)
-{
-	do_usercopy_heap_size(true);
-}
-
-void lkdtm_USERCOPY_HEAP_SIZE_FROM(void)
-{
-	do_usercopy_heap_size(false);
-}
-
-void lkdtm_USERCOPY_HEAP_WHITELIST_TO(void)
-{
-	do_usercopy_heap_whitelist(true);
-}
-
-void lkdtm_USERCOPY_HEAP_WHITELIST_FROM(void)
-{
-	do_usercopy_heap_whitelist(false);
-}
-
-void lkdtm_USERCOPY_STACK_FRAME_TO(void)
-{
-	do_usercopy_stack(true, true);
-}
-
-void lkdtm_USERCOPY_STACK_FRAME_FROM(void)
-{
-	do_usercopy_stack(false, true);
-}
-
-void lkdtm_USERCOPY_STACK_BEYOND(void)
-{
-	do_usercopy_stack(true, false);
-}
-
-void lkdtm_USERCOPY_KERNEL(void)
-{
-	unsigned long user_addr;
-
-	user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
-			    PROT_READ | PROT_WRITE | PROT_EXEC,
-			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
-	if (user_addr >= TASK_SIZE) {
-		pr_warn("Failed to allocate user memory\n");
-		return;
-	}
-
-	pr_info("attempting good copy_to_user from kernel rodata\n");
-	if (copy_to_user((void __user *)user_addr, test_text,
-			 unconst + sizeof(test_text))) {
-		pr_warn("copy_to_user failed unexpectedly?!\n");
-		goto free_user;
-	}
-
-	pr_info("attempting bad copy_to_user from kernel text\n");
-	if (copy_to_user((void __user *)user_addr, vm_mmap,
-			 unconst + PAGE_SIZE)) {
-		pr_warn("copy_to_user failed, but lacked Oops\n");
-		goto free_user;
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-}
-
-void __init lkdtm_usercopy_init(void)
-{
-	/* Prepare cache that lacks SLAB_USERCOPY flag. */
-	whitelist_cache =
-		kmem_cache_create_usercopy("lkdtm-usercopy", cache_size,
-					   0, 0,
-					   cache_size / 4,
-					   cache_size / 16,
-					   NULL);
-}
-
-void __exit lkdtm_usercopy_exit(void)
-{
-	kmem_cache_destroy(whitelist_cache);
-}