diff options
author | Kees Cook <keescook@chromium.org> | 2018-03-07 01:58:09 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-07 06:18:55 +0300 |
commit | 039a1c42058db54692a6d4497508bd48555f29fb (patch) | |
tree | 0fbd5a504e8a3cdf0cffd7e6bd0c41332f3e55d0 /drivers/misc/lkdtm_perms.c | |
parent | 37b96a4931dba07cebbf07092e55d1562155412b (diff) | |
download | linux-039a1c42058db54692a6d4497508bd48555f29fb.tar.xz |
lkdtm: Relocate code to subdirectory
The LKDTM modules keep expanding, and it's getting weird to have each file
get a prefix. Instead, move to a subdirectory for cleaner handling.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/lkdtm_perms.c')
-rw-r--r-- | drivers/misc/lkdtm_perms.c | 203 |
1 files changed, 0 insertions, 203 deletions
diff --git a/drivers/misc/lkdtm_perms.c b/drivers/misc/lkdtm_perms.c deleted file mode 100644 index 53b85c9d16b8..000000000000 --- a/drivers/misc/lkdtm_perms.c +++ /dev/null @@ -1,203 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * This is for all the tests related to validating kernel memory - * permissions: non-executable regions, non-writable regions, and - * even non-readable regions. - */ -#include "lkdtm.h" -#include <linux/slab.h> -#include <linux/vmalloc.h> -#include <linux/mman.h> -#include <linux/uaccess.h> -#include <asm/cacheflush.h> - -/* Whether or not to fill the target memory area with do_nothing(). */ -#define CODE_WRITE true -#define CODE_AS_IS false - -/* How many bytes to copy to be sure we've copied enough of do_nothing(). */ -#define EXEC_SIZE 64 - -/* This is non-const, so it will end up in the .data section. */ -static u8 data_area[EXEC_SIZE]; - -/* This is cost, so it will end up in the .rodata section. */ -static const unsigned long rodata = 0xAA55AA55; - -/* This is marked __ro_after_init, so it should ultimately be .rodata. */ -static unsigned long ro_after_init __ro_after_init = 0x55AA5500; - -/* - * This just returns to the caller. It is designed to be copied into - * non-executable memory regions. - */ -static void do_nothing(void) -{ - return; -} - -/* Must immediately follow do_nothing for size calculuations to work out. */ -static void do_overwritten(void) -{ - pr_info("do_overwritten wasn't overwritten!\n"); - return; -} - -static noinline void execute_location(void *dst, bool write) -{ - void (*func)(void) = dst; - - pr_info("attempting ok execution at %p\n", do_nothing); - do_nothing(); - - if (write == CODE_WRITE) { - memcpy(dst, do_nothing, EXEC_SIZE); - flush_icache_range((unsigned long)dst, - (unsigned long)dst + EXEC_SIZE); - } - pr_info("attempting bad execution at %p\n", func); - func(); -} - -static void execute_user_location(void *dst) -{ - int copied; - - /* Intentionally crossing kernel/user memory boundary. */ - void (*func)(void) = dst; - - pr_info("attempting ok execution at %p\n", do_nothing); - do_nothing(); - - copied = access_process_vm(current, (unsigned long)dst, do_nothing, - EXEC_SIZE, FOLL_WRITE); - if (copied < EXEC_SIZE) - return; - pr_info("attempting bad execution at %p\n", func); - func(); -} - -void lkdtm_WRITE_RO(void) -{ - /* Explicitly cast away "const" for the test. */ - unsigned long *ptr = (unsigned long *)&rodata; - - pr_info("attempting bad rodata write at %p\n", ptr); - *ptr ^= 0xabcd1234; -} - -void lkdtm_WRITE_RO_AFTER_INIT(void) -{ - unsigned long *ptr = &ro_after_init; - - /* - * Verify we were written to during init. Since an Oops - * is considered a "success", a failure is to just skip the - * real test. - */ - if ((*ptr & 0xAA) != 0xAA) { - pr_info("%p was NOT written during init!?\n", ptr); - return; - } - - pr_info("attempting bad ro_after_init write at %p\n", ptr); - *ptr ^= 0xabcd1234; -} - -void lkdtm_WRITE_KERN(void) -{ - size_t size; - unsigned char *ptr; - - size = (unsigned long)do_overwritten - (unsigned long)do_nothing; - ptr = (unsigned char *)do_overwritten; - - pr_info("attempting bad %zu byte write at %p\n", size, ptr); - memcpy(ptr, (unsigned char *)do_nothing, size); - flush_icache_range((unsigned long)ptr, (unsigned long)(ptr + size)); - - do_overwritten(); -} - -void lkdtm_EXEC_DATA(void) -{ - execute_location(data_area, CODE_WRITE); -} - -void lkdtm_EXEC_STACK(void) -{ - u8 stack_area[EXEC_SIZE]; - execute_location(stack_area, CODE_WRITE); -} - -void lkdtm_EXEC_KMALLOC(void) -{ - u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL); - execute_location(kmalloc_area, CODE_WRITE); - kfree(kmalloc_area); -} - -void lkdtm_EXEC_VMALLOC(void) -{ - u32 *vmalloc_area = vmalloc(EXEC_SIZE); - execute_location(vmalloc_area, CODE_WRITE); - vfree(vmalloc_area); -} - -void lkdtm_EXEC_RODATA(void) -{ - execute_location(lkdtm_rodata_do_nothing, CODE_AS_IS); -} - -void lkdtm_EXEC_USERSPACE(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; - } - execute_user_location((void *)user_addr); - vm_munmap(user_addr, PAGE_SIZE); -} - -void lkdtm_ACCESS_USERSPACE(void) -{ - unsigned long user_addr, tmp = 0; - unsigned long *ptr; - - 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 (copy_to_user((void __user *)user_addr, &tmp, sizeof(tmp))) { - pr_warn("copy_to_user failed\n"); - vm_munmap(user_addr, PAGE_SIZE); - return; - } - - ptr = (unsigned long *)user_addr; - - pr_info("attempting bad read at %p\n", ptr); - tmp = *ptr; - tmp += 0xc0dec0de; - - pr_info("attempting bad write at %p\n", ptr); - *ptr = tmp; - - vm_munmap(user_addr, PAGE_SIZE); -} - -void __init lkdtm_perms_init(void) -{ - /* Make sure we can write to __ro_after_init values during __init */ - ro_after_init |= 0xAA; - -} |