Add new crash locations that attempt to execute non-executable memory
regions (data segment, stack, kmalloc, vmalloc).
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
drivers/misc/lkdtm.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index 8bc7f0b..2fc0586 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -43,6 +43,7 @@
#include <linux/slab.h>
#include <scsi/scsi_cmnd.h>
#include <linux/debugfs.h>
+#include <linux/vmalloc.h>
#ifdef CONFIG_IDE
#include <linux/ide.h>
@@ -50,6 +51,7 @@
#define DEFAULT_COUNT 10
#define REC_NUM_DEFAULT 10
+#define EXEC_SIZE 64
enum cname {
CN_INVALID,
@@ -80,6 +82,10 @@ enum ctype {
CT_HARDLOCKUP,
CT_SPINLOCKUP,
CT_HUNG_TASK,
+ CT_EXEC_DATA,
+ CT_EXEC_STACK,
+ CT_EXEC_KMALLOC,
+ CT_EXEC_VMALLOC,
};
static char* cp_name[] = {
@@ -109,6 +115,10 @@ static char* cp_type[] = {
"HARDLOCKUP",
"SPINLOCKUP",
"HUNG_TASK",
+ "EXEC_DATA",
+ "EXEC_STACK",
+ "EXEC_KMALLOC",
+ "EXEC_VMALLOC",
};
static struct jprobe lkdtm;
@@ -127,6 +137,8 @@ static int count = DEFAULT_COUNT;
static DEFINE_SPINLOCK(count_lock);
static DEFINE_SPINLOCK(lock_me_up);
+static u8 data_area[EXEC_SIZE];
+
module_param(recur_count, int, 0644);
MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
"default is 10");
@@ -280,6 +292,19 @@ static int recursive_loop(int a)
return recursive_loop(a);
}
+static void do_nothing(void)
+{
+ return;
+}
+
+static void execute_location(void *dst)
+{
+ void (*func)(void) = dst;
+
+ memcpy(dst, do_nothing, EXEC_SIZE);
+ func();
+}
+
static void lkdtm_do_action(enum ctype which)
{
switch (which) {
@@ -356,6 +381,26 @@ static void lkdtm_do_action(enum ctype which)
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
break;
+ case CT_EXEC_DATA:
+ execute_location(data_area);
+ break;
+ case CT_EXEC_STACK: {
+ u8 stack_area[EXEC_SIZE];
+ execute_location(stack_area);
+ break;
+ }
+ case CT_EXEC_KMALLOC: {
+ u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
+ execute_location(kmalloc_area);
+ kfree(kmalloc_area);
+ break;
+ }
+ case CT_EXEC_VMALLOC: {
+ u32 *vmalloc_area = vmalloc(EXEC_SIZE);
+ execute_location(vmalloc_area);
+ vfree(vmalloc_area);
+ break;
+ }
case CT_NONE:
default:
break;
--
1.7.9.5
--
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