lkdtm: split usercopy tests to separate file
This splits the USERCOPY_* tests into the new lkdtm_usercopy.c file to help separate things better for readability. Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook
@@ -60,6 +60,7 @@ obj-$(CONFIG_PANEL) += panel.o
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lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
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lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
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lkdtm-$(CONFIG_LKDTM) += lkdtm_rodata_objcopy.o
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lkdtm-$(CONFIG_LKDTM) += lkdtm_rodata_objcopy.o
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lkdtm-$(CONFIG_LKDTM) += lkdtm_usercopy.o
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OBJCOPYFLAGS :=
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OBJCOPYFLAGS :=
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OBJCOPYFLAGS_lkdtm_rodata_objcopy.o := \
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OBJCOPYFLAGS_lkdtm_rodata_objcopy.o := \
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@@ -1,6 +1,19 @@
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#ifndef __LKDTM_H
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#ifndef __LKDTM_H
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#define __LKDTM_H
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#define __LKDTM_H
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/* lkdtm_rodata.c */
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void lkdtm_rodata_do_nothing(void);
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void lkdtm_rodata_do_nothing(void);
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/* lkdtm_usercopy.c */
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void __init lkdtm_usercopy_init(void);
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void __exit lkdtm_usercopy_exit(void);
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void lkdtm_USERCOPY_HEAP_SIZE_TO(void);
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void lkdtm_USERCOPY_HEAP_SIZE_FROM(void);
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void lkdtm_USERCOPY_HEAP_FLAG_TO(void);
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void lkdtm_USERCOPY_HEAP_FLAG_FROM(void);
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void lkdtm_USERCOPY_STACK_FRAME_TO(void);
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void lkdtm_USERCOPY_STACK_FRAME_FROM(void);
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void lkdtm_USERCOPY_STACK_BEYOND(void);
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void lkdtm_USERCOPY_KERNEL(void);
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#endif
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#endif
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@@ -193,10 +193,6 @@ static DEFINE_SPINLOCK(lock_me_up);
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static u8 data_area[EXEC_SIZE];
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static u8 data_area[EXEC_SIZE];
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static size_t cache_size = 1024;
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static struct kmem_cache *bad_cache;
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static const unsigned char test_text[] = "This is a test.\n";
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static const unsigned long rodata = 0xAA55AA55;
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static const unsigned long rodata = 0xAA55AA55;
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static unsigned long ro_after_init __ro_after_init = 0x55AA5500;
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static unsigned long ro_after_init __ro_after_init = 0x55AA5500;
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@@ -403,255 +399,6 @@ static void execute_user_location(void *dst)
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func();
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func();
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}
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}
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/*
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* Instead of adding -Wno-return-local-addr, just pass the stack address
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* through a function to obfuscate it from the compiler.
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*/
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static noinline unsigned char *trick_compiler(unsigned char *stack)
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{
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return stack + 0;
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}
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static noinline unsigned char *do_usercopy_stack_callee(int value)
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{
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unsigned char buf[32];
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int i;
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/* Exercise stack to avoid everything living in registers. */
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for (i = 0; i < sizeof(buf); i++) {
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buf[i] = value & 0xff;
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}
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return trick_compiler(buf);
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}
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static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
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{
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unsigned long user_addr;
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unsigned char good_stack[32];
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unsigned char *bad_stack;
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int i;
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/* Exercise stack to avoid everything living in registers. */
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for (i = 0; i < sizeof(good_stack); i++)
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good_stack[i] = test_text[i % sizeof(test_text)];
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/* This is a pointer to outside our current stack frame. */
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if (bad_frame) {
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bad_stack = do_usercopy_stack_callee((uintptr_t)bad_stack);
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} else {
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/* Put start address just inside stack. */
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bad_stack = task_stack_page(current) + THREAD_SIZE;
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bad_stack -= sizeof(unsigned long);
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}
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user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_ANONYMOUS | MAP_PRIVATE, 0);
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if (user_addr >= TASK_SIZE) {
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pr_warn("Failed to allocate user memory\n");
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return;
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}
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if (to_user) {
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pr_info("attempting good copy_to_user of local stack\n");
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if (copy_to_user((void __user *)user_addr, good_stack,
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sizeof(good_stack))) {
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pr_warn("copy_to_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_to_user of distant stack\n");
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if (copy_to_user((void __user *)user_addr, bad_stack,
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sizeof(good_stack))) {
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pr_warn("copy_to_user failed, but lacked Oops\n");
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goto free_user;
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}
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} else {
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/*
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* There isn't a safe way to not be protected by usercopy
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* if we're going to write to another thread's stack.
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*/
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if (!bad_frame)
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goto free_user;
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pr_info("attempting good copy_from_user of local stack\n");
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if (copy_from_user(good_stack, (void __user *)user_addr,
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sizeof(good_stack))) {
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pr_warn("copy_from_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_from_user of distant stack\n");
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if (copy_from_user(bad_stack, (void __user *)user_addr,
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sizeof(good_stack))) {
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pr_warn("copy_from_user failed, but lacked Oops\n");
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goto free_user;
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}
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}
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free_user:
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vm_munmap(user_addr, PAGE_SIZE);
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}
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static void do_usercopy_kernel(void)
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{
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unsigned long user_addr;
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user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_ANONYMOUS | MAP_PRIVATE, 0);
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if (user_addr >= TASK_SIZE) {
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pr_warn("Failed to allocate user memory\n");
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return;
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}
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pr_info("attempting good copy_to_user from kernel rodata\n");
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if (copy_to_user((void __user *)user_addr, test_text,
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sizeof(test_text))) {
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pr_warn("copy_to_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_to_user from kernel text\n");
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if (copy_to_user((void __user *)user_addr, vm_mmap, PAGE_SIZE)) {
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pr_warn("copy_to_user failed, but lacked Oops\n");
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goto free_user;
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}
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free_user:
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vm_munmap(user_addr, PAGE_SIZE);
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}
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static void do_usercopy_heap_size(bool to_user)
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{
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unsigned long user_addr;
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unsigned char *one, *two;
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size_t size = 1024;
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one = kmalloc(size, GFP_KERNEL);
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two = kmalloc(size, GFP_KERNEL);
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if (!one || !two) {
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pr_warn("Failed to allocate kernel memory\n");
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goto free_kernel;
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}
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user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_ANONYMOUS | MAP_PRIVATE, 0);
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if (user_addr >= TASK_SIZE) {
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pr_warn("Failed to allocate user memory\n");
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goto free_kernel;
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}
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memset(one, 'A', size);
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memset(two, 'B', size);
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if (to_user) {
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pr_info("attempting good copy_to_user of correct size\n");
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if (copy_to_user((void __user *)user_addr, one, size)) {
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pr_warn("copy_to_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_to_user of too large size\n");
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if (copy_to_user((void __user *)user_addr, one, 2 * size)) {
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pr_warn("copy_to_user failed, but lacked Oops\n");
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goto free_user;
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}
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} else {
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pr_info("attempting good copy_from_user of correct size\n");
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if (copy_from_user(one, (void __user *)user_addr, size)) {
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pr_warn("copy_from_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_from_user of too large size\n");
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if (copy_from_user(one, (void __user *)user_addr, 2 * size)) {
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pr_warn("copy_from_user failed, but lacked Oops\n");
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goto free_user;
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}
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}
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free_user:
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vm_munmap(user_addr, PAGE_SIZE);
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free_kernel:
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kfree(one);
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kfree(two);
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}
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static void do_usercopy_heap_flag(bool to_user)
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{
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unsigned long user_addr;
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unsigned char *good_buf = NULL;
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unsigned char *bad_buf = NULL;
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/* Make sure cache was prepared. */
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if (!bad_cache) {
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pr_warn("Failed to allocate kernel cache\n");
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return;
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}
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/*
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* Allocate one buffer from each cache (kmalloc will have the
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* SLAB_USERCOPY flag already, but "bad_cache" won't).
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*/
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good_buf = kmalloc(cache_size, GFP_KERNEL);
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bad_buf = kmem_cache_alloc(bad_cache, GFP_KERNEL);
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if (!good_buf || !bad_buf) {
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pr_warn("Failed to allocate buffers from caches\n");
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goto free_alloc;
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}
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/* Allocate user memory we'll poke at. */
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user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_ANONYMOUS | MAP_PRIVATE, 0);
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if (user_addr >= TASK_SIZE) {
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pr_warn("Failed to allocate user memory\n");
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goto free_alloc;
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}
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memset(good_buf, 'A', cache_size);
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memset(bad_buf, 'B', cache_size);
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if (to_user) {
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pr_info("attempting good copy_to_user with SLAB_USERCOPY\n");
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if (copy_to_user((void __user *)user_addr, good_buf,
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cache_size)) {
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pr_warn("copy_to_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_to_user w/o SLAB_USERCOPY\n");
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if (copy_to_user((void __user *)user_addr, bad_buf,
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cache_size)) {
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pr_warn("copy_to_user failed, but lacked Oops\n");
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goto free_user;
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}
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} else {
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pr_info("attempting good copy_from_user with SLAB_USERCOPY\n");
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if (copy_from_user(good_buf, (void __user *)user_addr,
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cache_size)) {
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pr_warn("copy_from_user failed unexpectedly?!\n");
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goto free_user;
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}
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pr_info("attempting bad copy_from_user w/o SLAB_USERCOPY\n");
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if (copy_from_user(bad_buf, (void __user *)user_addr,
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cache_size)) {
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pr_warn("copy_from_user failed, but lacked Oops\n");
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goto free_user;
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}
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}
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free_user:
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vm_munmap(user_addr, PAGE_SIZE);
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free_alloc:
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if (bad_buf)
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kmem_cache_free(bad_cache, bad_buf);
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kfree(good_buf);
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}
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static void lkdtm_do_action(enum ctype which)
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static void lkdtm_do_action(enum ctype which)
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{
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{
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@@ -964,28 +711,28 @@ static void lkdtm_do_action(enum ctype which)
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return;
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return;
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}
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}
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case CT_USERCOPY_HEAP_SIZE_TO:
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case CT_USERCOPY_HEAP_SIZE_TO:
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do_usercopy_heap_size(true);
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lkdtm_USERCOPY_HEAP_SIZE_TO();
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break;
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break;
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case CT_USERCOPY_HEAP_SIZE_FROM:
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case CT_USERCOPY_HEAP_SIZE_FROM:
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do_usercopy_heap_size(false);
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lkdtm_USERCOPY_HEAP_SIZE_FROM();
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break;
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break;
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case CT_USERCOPY_HEAP_FLAG_TO:
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case CT_USERCOPY_HEAP_FLAG_TO:
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do_usercopy_heap_flag(true);
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lkdtm_USERCOPY_HEAP_FLAG_TO();
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break;
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break;
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case CT_USERCOPY_HEAP_FLAG_FROM:
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case CT_USERCOPY_HEAP_FLAG_FROM:
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do_usercopy_heap_flag(false);
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lkdtm_USERCOPY_HEAP_FLAG_FROM();
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break;
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break;
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case CT_USERCOPY_STACK_FRAME_TO:
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case CT_USERCOPY_STACK_FRAME_TO:
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do_usercopy_stack(true, true);
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lkdtm_USERCOPY_STACK_FRAME_TO();
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break;
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break;
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case CT_USERCOPY_STACK_FRAME_FROM:
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case CT_USERCOPY_STACK_FRAME_FROM:
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do_usercopy_stack(false, true);
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lkdtm_USERCOPY_STACK_FRAME_FROM();
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break;
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break;
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case CT_USERCOPY_STACK_BEYOND:
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case CT_USERCOPY_STACK_BEYOND:
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do_usercopy_stack(true, false);
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lkdtm_USERCOPY_STACK_BEYOND();
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break;
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break;
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case CT_USERCOPY_KERNEL:
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case CT_USERCOPY_KERNEL:
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do_usercopy_kernel();
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lkdtm_USERCOPY_KERNEL();
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break;
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break;
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case CT_NONE:
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case CT_NONE:
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default:
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default:
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@@ -1276,13 +1023,12 @@ static int __init lkdtm_module_init(void)
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int n_debugfs_entries = 1; /* Assume only the direct entry */
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int n_debugfs_entries = 1; /* Assume only the direct entry */
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int i;
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int i;
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/* Handle test-specific initialization. */
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lkdtm_usercopy_init();
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/* Make sure we can write to __ro_after_init values during __init */
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/* Make sure we can write to __ro_after_init values during __init */
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ro_after_init |= 0xAA;
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ro_after_init |= 0xAA;
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/* Prepare cache that lacks SLAB_USERCOPY flag. */
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bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0,
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0, NULL);
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/* Register debugfs interface */
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/* Register debugfs interface */
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lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
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lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
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if (!lkdtm_debugfs_root) {
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if (!lkdtm_debugfs_root) {
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@@ -1334,7 +1080,8 @@ static void __exit lkdtm_module_exit(void)
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{
|
{
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debugfs_remove_recursive(lkdtm_debugfs_root);
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debugfs_remove_recursive(lkdtm_debugfs_root);
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kmem_cache_destroy(bad_cache);
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/* Handle test-specific clean-up. */
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lkdtm_usercopy_exit();
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|
||||||
unregister_jprobe(&lkdtm);
|
unregister_jprobe(&lkdtm);
|
||||||
pr_info("Crash point unregistered\n");
|
pr_info("Crash point unregistered\n");
|
||||||
|
|||||||
315
drivers/misc/lkdtm_usercopy.c
Normal file
315
drivers/misc/lkdtm_usercopy.c
Normal file
@@ -0,0 +1,315 @@
|
|||||||
|
/*
|
||||||
|
* This is for all the tests related to copy_to_user() and copy_from_user()
|
||||||
|
* hardening.
|
||||||
|
*/
|
||||||
|
#define pr_fmt(fmt) "lkdtm: " fmt
|
||||||
|
|
||||||
|
#include <linux/kernel.h>
|
||||||
|
#include <linux/slab.h>
|
||||||
|
#include <linux/vmalloc.h>
|
||||||
|
#include <linux/mman.h>
|
||||||
|
#include <linux/uaccess.h>
|
||||||
|
#include <asm/cacheflush.h>
|
||||||
|
|
||||||
|
static size_t cache_size = 1024;
|
||||||
|
static struct kmem_cache *bad_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,
|
||||||
|
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,
|
||||||
|
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,
|
||||||
|
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,
|
||||||
|
sizeof(good_stack))) {
|
||||||
|
pr_warn("copy_from_user failed, but lacked Oops\n");
|
||||||
|
goto free_user;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
free_user:
|
||||||
|
vm_munmap(user_addr, PAGE_SIZE);
|
||||||
|
}
|
||||||
|
|
||||||
|
static void do_usercopy_heap_size(bool to_user)
|
||||||
|
{
|
||||||
|
unsigned long user_addr;
|
||||||
|
unsigned char *one, *two;
|
||||||
|
const size_t size = 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);
|
||||||
|
|
||||||
|
if (to_user) {
|
||||||
|
pr_info("attempting good copy_to_user of correct size\n");
|
||||||
|
if (copy_to_user((void __user *)user_addr, one, size)) {
|
||||||
|
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((void __user *)user_addr, one, 2 * 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(one, (void __user *)user_addr, size)) {
|
||||||
|
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(one, (void __user *)user_addr, 2 * 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);
|
||||||
|
}
|
||||||
|
|
||||||
|
static void do_usercopy_heap_flag(bool to_user)
|
||||||
|
{
|
||||||
|
unsigned long user_addr;
|
||||||
|
unsigned char *good_buf = NULL;
|
||||||
|
unsigned char *bad_buf = NULL;
|
||||||
|
|
||||||
|
/* Make sure cache was prepared. */
|
||||||
|
if (!bad_cache) {
|
||||||
|
pr_warn("Failed to allocate kernel cache\n");
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Allocate one buffer from each cache (kmalloc will have the
|
||||||
|
* SLAB_USERCOPY flag already, but "bad_cache" won't).
|
||||||
|
*/
|
||||||
|
good_buf = kmalloc(cache_size, GFP_KERNEL);
|
||||||
|
bad_buf = kmem_cache_alloc(bad_cache, GFP_KERNEL);
|
||||||
|
if (!good_buf || !bad_buf) {
|
||||||
|
pr_warn("Failed to allocate buffers from caches\n");
|
||||||
|
goto free_alloc;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Allocate user memory we'll poke at. */
|
||||||
|
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_alloc;
|
||||||
|
}
|
||||||
|
|
||||||
|
memset(good_buf, 'A', cache_size);
|
||||||
|
memset(bad_buf, 'B', cache_size);
|
||||||
|
|
||||||
|
if (to_user) {
|
||||||
|
pr_info("attempting good copy_to_user with SLAB_USERCOPY\n");
|
||||||
|
if (copy_to_user((void __user *)user_addr, good_buf,
|
||||||
|
cache_size)) {
|
||||||
|
pr_warn("copy_to_user failed unexpectedly?!\n");
|
||||||
|
goto free_user;
|
||||||
|
}
|
||||||
|
|
||||||
|
pr_info("attempting bad copy_to_user w/o SLAB_USERCOPY\n");
|
||||||
|
if (copy_to_user((void __user *)user_addr, bad_buf,
|
||||||
|
cache_size)) {
|
||||||
|
pr_warn("copy_to_user failed, but lacked Oops\n");
|
||||||
|
goto free_user;
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
pr_info("attempting good copy_from_user with SLAB_USERCOPY\n");
|
||||||
|
if (copy_from_user(good_buf, (void __user *)user_addr,
|
||||||
|
cache_size)) {
|
||||||
|
pr_warn("copy_from_user failed unexpectedly?!\n");
|
||||||
|
goto free_user;
|
||||||
|
}
|
||||||
|
|
||||||
|
pr_info("attempting bad copy_from_user w/o SLAB_USERCOPY\n");
|
||||||
|
if (copy_from_user(bad_buf, (void __user *)user_addr,
|
||||||
|
cache_size)) {
|
||||||
|
pr_warn("copy_from_user failed, but lacked Oops\n");
|
||||||
|
goto free_user;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
free_user:
|
||||||
|
vm_munmap(user_addr, PAGE_SIZE);
|
||||||
|
free_alloc:
|
||||||
|
if (bad_buf)
|
||||||
|
kmem_cache_free(bad_cache, bad_buf);
|
||||||
|
kfree(good_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_FLAG_TO(void)
|
||||||
|
{
|
||||||
|
do_usercopy_heap_flag(true);
|
||||||
|
}
|
||||||
|
|
||||||
|
void lkdtm_USERCOPY_HEAP_FLAG_FROM(void)
|
||||||
|
{
|
||||||
|
do_usercopy_heap_flag(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,
|
||||||
|
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, 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. */
|
||||||
|
bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0,
|
||||||
|
0, NULL);
|
||||||
|
}
|
||||||
|
|
||||||
|
void __exit lkdtm_usercopy_exit(void)
|
||||||
|
{
|
||||||
|
kmem_cache_destroy(bad_cache);
|
||||||
|
}
|
||||||
Reference in New Issue
Block a user