diff options
Diffstat (limited to 'drivers/misc/lkdtm.c')
| -rw-r--r-- | drivers/misc/lkdtm.c | 107 |
1 files changed, 16 insertions, 91 deletions
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c index a2edb2e..2fc0586 100644 --- a/drivers/misc/lkdtm.c +++ b/drivers/misc/lkdtm.c @@ -44,25 +44,13 @@ #include <scsi/scsi_cmnd.h> #include <linux/debugfs.h> #include <linux/vmalloc.h> -#include <linux/mman.h> #ifdef CONFIG_IDE #include <linux/ide.h> #endif -/* - * 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 +#define REC_NUM_DEFAULT 10 #define EXEC_SIZE 64 enum cname { @@ -98,9 +86,6 @@ enum ctype { CT_EXEC_STACK, CT_EXEC_KMALLOC, CT_EXEC_VMALLOC, - CT_EXEC_USERSPACE, - CT_ACCESS_USERSPACE, - CT_WRITE_RO, }; static char* cp_name[] = { @@ -134,9 +119,6 @@ static char* cp_type[] = { "EXEC_STACK", "EXEC_KMALLOC", "EXEC_VMALLOC", - "EXEC_USERSPACE", - "ACCESS_USERSPACE", - "WRITE_RO", }; static struct jprobe lkdtm; @@ -157,10 +139,9 @@ static DEFINE_SPINLOCK(lock_me_up); static u8 data_area[EXEC_SIZE]; -static const unsigned long rodata = 0xAA55AA55; - module_param(recur_count, int, 0644); -MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test"); +MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\ + "default is 10"); module_param(cpoint_name, charp, 0444); MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed"); module_param(cpoint_type, charp, 0444); @@ -299,16 +280,16 @@ static int lkdtm_parse_commandline(void) return -EINVAL; } -static int recursive_loop(int remaining) +static int recursive_loop(int a) { - char buf[REC_STACK_SIZE]; + char buf[1024]; - /* Make sure compiler does not optimize this away. */ - memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE); - if (!remaining) + memset(buf,0xFF,1024); + recur_count--; + if (!recur_count) return 0; else - return recursive_loop(remaining - 1); + return recursive_loop(a); } static void do_nothing(void) @@ -316,14 +297,6 @@ static void do_nothing(void) return; } -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 execute_location(void *dst) { void (*func)(void) = dst; @@ -332,15 +305,6 @@ static void execute_location(void *dst) func(); } -static void execute_user_location(void *dst) -{ - void (*func)(void) = dst; - - if (copy_to_user(dst, do_nothing, EXEC_SIZE)) - return; - func(); -} - static void lkdtm_do_action(enum ctype which) { switch (which) { @@ -361,11 +325,15 @@ static void lkdtm_do_action(enum ctype which) ; break; case CT_OVERFLOW: - (void) recursive_loop(recur_count); + (void) recursive_loop(0); break; - case CT_CORRUPT_STACK: - corrupt_stack(); + case CT_CORRUPT_STACK: { + /* Make sure the compiler creates and uses an 8 char array. */ + volatile char data[8]; + + memset((void *)data, 0, 64); break; + } case CT_UNALIGNED_LOAD_STORE_WRITE: { static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5}; @@ -433,49 +401,6 @@ static void lkdtm_do_action(enum ctype which) vfree(vmalloc_area); break; } - case CT_EXEC_USERSPACE: { - 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); - break; - } - case CT_ACCESS_USERSPACE: { - unsigned long user_addr, tmp; - 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; - } - - ptr = (unsigned long *)user_addr; - tmp = *ptr; - tmp += 0xc0dec0de; - *ptr = tmp; - - vm_munmap(user_addr, PAGE_SIZE); - - break; - } - case CT_WRITE_RO: { - unsigned long *ptr; - - ptr = (unsigned long *)&rodata; - *ptr ^= 0xabcd1234; - - break; - } case CT_NONE: default: break; |