pthread : Add null check at pthread_getstacksize
Without this condition, null dereference assert will occur
@@ -106,7 +106,7 @@ int pthread_attr_getstacksize(FAR const pthread_attr_t *attr, FAR long *stacksiz
sdbg("attr=0x%p stacksize=0x%p\n", attr, stacksize);
- if (!stacksize) {
+ if (!attr || !stacksize) {
ret = EINVAL;
} else {
*stacksize = attr->stacksize;
