lkdtm: split remaining logic bug tests to separate file

This splits all the remaining tests from lkdtm_core.c into the new
lkdtm_bugs.c file to help separate things better for readability.

Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2016-06-26 22:17:25 -07:00
parent ffc514f3fc
commit 00f496c416
4 changed files with 194 additions and 90 deletions

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@ -59,6 +59,7 @@ obj-$(CONFIG_CXL_BASE) += cxl/
obj-$(CONFIG_PANEL) += panel.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_bugs.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_heap.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_perms.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_rodata_objcopy.o

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@ -1,6 +1,23 @@
#ifndef __LKDTM_H
#define __LKDTM_H
/* lkdtm_bugs.c */
void __init lkdtm_bugs_init(int *recur_param);
void lkdtm_PANIC(void);
void lkdtm_BUG(void);
void lkdtm_WARNING(void);
void lkdtm_EXCEPTION(void);
void lkdtm_LOOP(void);
void lkdtm_OVERFLOW(void);
void lkdtm_CORRUPT_STACK(void);
void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void);
void lkdtm_SOFTLOCKUP(void);
void lkdtm_HARDLOCKUP(void);
void lkdtm_SPINLOCKUP(void);
void lkdtm_HUNG_TASK(void);
void lkdtm_ATOMIC_UNDERFLOW(void);
void lkdtm_ATOMIC_OVERFLOW(void);
/* lkdtm_heap.c */
void lkdtm_OVERWRITE_ALLOCATION(void);
void lkdtm_WRITE_AFTER_FREE(void);

152
drivers/misc/lkdtm_bugs.c Normal file
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@ -0,0 +1,152 @@
/*
* This is for all the tests related to logic bugs (e.g. bad dereferences,
* bad alignment, bad loops, bad locking, bad scheduling, deep stacks, and
* lockups) along with other things that don't fit well into existing LKDTM
* test source files.
*/
#define pr_fmt(fmt) "lkdtm: " fmt
#include <linux/kernel.h>
#include <linux/sched.h>
#include "lkdtm.h"
/*
* Make sure our attempts to over run the kernel stack doesn't trigger
* a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
* recurse past the end of THREAD_SIZE by default.
*/
#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
#else
#define REC_STACK_SIZE (THREAD_SIZE / 8)
#endif
#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
static int recur_count = REC_NUM_DEFAULT;
static DEFINE_SPINLOCK(lock_me_up);
static int recursive_loop(int remaining)
{
char buf[REC_STACK_SIZE];
/* Make sure compiler does not optimize this away. */
memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
if (!remaining)
return 0;
else
return recursive_loop(remaining - 1);
}
/* If the depth is negative, use the default, otherwise keep parameter. */
void __init lkdtm_bugs_init(int *recur_param)
{
if (*recur_param < 0)
*recur_param = recur_count;
else
recur_count = *recur_param;
}
void lkdtm_PANIC(void)
{
panic("dumptest");
}
void lkdtm_BUG(void)
{
BUG();
}
void lkdtm_WARNING(void)
{
WARN_ON(1);
}
void lkdtm_EXCEPTION(void)
{
*((int *) 0) = 0;
}
void lkdtm_LOOP(void)
{
for (;;)
;
}
void lkdtm_OVERFLOW(void)
{
(void) recursive_loop(recur_count);
}
noinline void lkdtm_CORRUPT_STACK(void)
{
/* Use default char array length that triggers stack protection. */
char data[8];
memset((void *)data, 0, 64);
}
void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
{
static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5};
u32 *p;
u32 val = 0x12345678;
p = (u32 *)(data + 1);
if (*p == 0)
val = 0x87654321;
*p = val;
}
void lkdtm_SOFTLOCKUP(void)
{
preempt_disable();
for (;;)
cpu_relax();
}
void lkdtm_HARDLOCKUP(void)
{
local_irq_disable();
for (;;)
cpu_relax();
}
void lkdtm_SPINLOCKUP(void)
{
/* Must be called twice to trigger. */
spin_lock(&lock_me_up);
/* Let sparse know we intended to exit holding the lock. */
__release(&lock_me_up);
}
void lkdtm_HUNG_TASK(void)
{
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
}
void lkdtm_ATOMIC_UNDERFLOW(void)
{
atomic_t under = ATOMIC_INIT(INT_MIN);
pr_info("attempting good atomic increment\n");
atomic_inc(&under);
atomic_dec(&under);
pr_info("attempting bad atomic underflow\n");
atomic_dec(&under);
}
void lkdtm_ATOMIC_OVERFLOW(void)
{
atomic_t over = ATOMIC_INIT(INT_MAX);
pr_info("attempting good atomic decrement\n");
atomic_dec(&over);
atomic_inc(&over);
pr_info("attempting bad atomic overflow\n");
atomic_inc(&over);
}

View File

@ -51,20 +51,11 @@
#include "lkdtm.h"
/*
* Make sure our attempts to over run the kernel stack doesn't trigger
* a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
* recurse past the end of THREAD_SIZE by default.
*/
#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
#else
#define REC_STACK_SIZE (THREAD_SIZE / 8)
#endif
#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
#define DEFAULT_COUNT 10
static int count = DEFAULT_COUNT;
static DEFINE_SPINLOCK(count_lock);
enum cname {
CN_INVALID,
CN_INT_HARDWARE_ENTRY,
@ -179,13 +170,10 @@ static void lkdtm_handler(void);
static char* cpoint_name;
static char* cpoint_type;
static int cpoint_count = DEFAULT_COUNT;
static int recur_count = REC_NUM_DEFAULT;
static int recur_count = -1;
static enum cname cpoint = CN_INVALID;
static enum ctype cptype = CT_NONE;
static int count = DEFAULT_COUNT;
static DEFINE_SPINLOCK(count_lock);
static DEFINE_SPINLOCK(lock_me_up);
module_param(recur_count, int, 0644);
MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
@ -327,63 +315,33 @@ static int lkdtm_parse_commandline(void)
return -EINVAL;
}
static int recursive_loop(int remaining)
{
char buf[REC_STACK_SIZE];
/* Make sure compiler does not optimize this away. */
memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
if (!remaining)
return 0;
else
return recursive_loop(remaining - 1);
}
static noinline void corrupt_stack(void)
{
/* Use default char array length that triggers stack protection. */
char data[8];
memset((void *)data, 0, 64);
}
static void lkdtm_do_action(enum ctype which)
{
switch (which) {
case CT_PANIC:
panic("dumptest");
lkdtm_PANIC();
break;
case CT_BUG:
BUG();
lkdtm_BUG();
break;
case CT_WARNING:
WARN_ON(1);
lkdtm_WARNING();
break;
case CT_EXCEPTION:
*((int *) 0) = 0;
lkdtm_EXCEPTION();
break;
case CT_LOOP:
for (;;)
;
lkdtm_LOOP();
break;
case CT_OVERFLOW:
(void) recursive_loop(recur_count);
lkdtm_OVERFLOW();
break;
case CT_CORRUPT_STACK:
corrupt_stack();
lkdtm_CORRUPT_STACK();
break;
case CT_UNALIGNED_LOAD_STORE_WRITE:
lkdtm_UNALIGNED_LOAD_STORE_WRITE();
break;
case CT_UNALIGNED_LOAD_STORE_WRITE: {
static u8 data[5] __attribute__((aligned(4))) = {1, 2,
3, 4, 5};
u32 *p;
u32 val = 0x12345678;
p = (u32 *)(data + 1);
if (*p == 0)
val = 0x87654321;
*p = val;
break;
}
case CT_OVERWRITE_ALLOCATION:
lkdtm_OVERWRITE_ALLOCATION();
break;
@ -400,24 +358,16 @@ static void lkdtm_do_action(enum ctype which)
lkdtm_READ_BUDDY_AFTER_FREE();
break;
case CT_SOFTLOCKUP:
preempt_disable();
for (;;)
cpu_relax();
lkdtm_SOFTLOCKUP();
break;
case CT_HARDLOCKUP:
local_irq_disable();
for (;;)
cpu_relax();
lkdtm_HARDLOCKUP();
break;
case CT_SPINLOCKUP:
/* Must be called twice to trigger. */
spin_lock(&lock_me_up);
/* Let sparse know we intended to exit holding the lock. */
__release(&lock_me_up);
lkdtm_SPINLOCKUP();
break;
case CT_HUNG_TASK:
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
lkdtm_HUNG_TASK();
break;
case CT_EXEC_DATA:
lkdtm_EXEC_DATA();
@ -449,29 +399,12 @@ static void lkdtm_do_action(enum ctype which)
case CT_WRITE_KERN:
lkdtm_WRITE_KERN();
break;
case CT_ATOMIC_UNDERFLOW: {
atomic_t under = ATOMIC_INIT(INT_MIN);
pr_info("attempting good atomic increment\n");
atomic_inc(&under);
atomic_dec(&under);
pr_info("attempting bad atomic underflow\n");
atomic_dec(&under);
case CT_ATOMIC_UNDERFLOW:
lkdtm_ATOMIC_UNDERFLOW();
break;
case CT_ATOMIC_OVERFLOW:
lkdtm_ATOMIC_OVERFLOW();
break;
}
case CT_ATOMIC_OVERFLOW: {
atomic_t over = ATOMIC_INIT(INT_MAX);
pr_info("attempting good atomic decrement\n");
atomic_dec(&over);
atomic_inc(&over);
pr_info("attempting bad atomic overflow\n");
atomic_inc(&over);
return;
}
case CT_USERCOPY_HEAP_SIZE_TO:
lkdtm_USERCOPY_HEAP_SIZE_TO();
break;
@ -786,6 +719,7 @@ static int __init lkdtm_module_init(void)
int i;
/* Handle test-specific initialization. */
lkdtm_bugs_init(&recur_count);
lkdtm_perms_init();
lkdtm_usercopy_init();