X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fmisc%2Flkdtm.c;fp=kernel%2Fdrivers%2Fmisc%2Flkdtm.c;h=11fdadc68e53e57722b4d58892fdf2c644beba34;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=b5abe34120b8a9c2169e6bb8513e88bd8d49051c;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/drivers/misc/lkdtm.c b/kernel/drivers/misc/lkdtm.c
index b5abe3412..11fdadc68 100644
--- a/kernel/drivers/misc/lkdtm.c
+++ b/kernel/drivers/misc/lkdtm.c
@@ -472,7 +472,7 @@ static void lkdtm_do_action(enum ctype which)
 		break;
 	}
 	case CT_ACCESS_USERSPACE: {
-		unsigned long user_addr, tmp;
+		unsigned long user_addr, tmp = 0;
 		unsigned long *ptr;
 
 		user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
@@ -483,6 +483,12 @@ static void lkdtm_do_action(enum ctype which)
 			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);