Get object properties after `mrb_get_args()`
ref.
I checked with Valgrind, and the methods that can cause use-after-free are `Array#rotate`, `Array#rotate!`, and `String#byteslice`.
Since `String#rindex` uses `RSTRING_LEN()` indirectly inside the function, no reference to the out-of-bounds range is generated.
MODIFY
mrbgems/mruby-array-ext/src/array.c
mrbgems/mruby-array-ext/src/array.c
@@ -264,12 +264,14 @@ mrb_ary_compact_bang(mrb_state *mrb, mrb_value self)
static mrb_value
mrb_ary_rotate(mrb_state *mrb, mrb_value self)
{
+ mrb_int count=1;
+ mrb_get_args(mrb, "|i", &count);
+
mrb_value ary = mrb_ary_new(mrb);
mrb_int len = RARRAY_LEN(self);
mrb_value *p = RARRAY_PTR(self);
- mrb_int count=1, idx;
+ mrb_int idx;
- mrb_get_args(mrb, "|i", &count);
if (len <= 0) return ary;
if (count < 0) {
idx = len - (~count % len) - 1;
@@ -313,12 +315,14 @@ rev(mrb_value *p, mrb_int beg, mrb_int end)
static mrb_value
mrb_ary_rotate_bang(mrb_state *mrb, mrb_value self)
{
+ mrb_int count=1;
+ mrb_get_args(mrb, "|i", &count);
+
struct RArray *a = mrb_ary_ptr(self);
mrb_int len = ARY_LEN(a);
mrb_value *p = ARY_PTR(a);
- mrb_int count=1, idx;
+ mrb_int idx;
- mrb_get_args(mrb, "|i", &count);
mrb_ary_modify(mrb, a);
if (len == 0 || count == 0) return self;
if (count == 1) {

MODIFY
src/string.c
src/string.c
@@ -2047,9 +2047,11 @@ static mrb_value
mrb_str_rindex(mrb_state *mrb, mrb_value str)
{
mrb_value sub;
- mrb_int pos, len = RSTRING_CHAR_LEN(str);
+ mrb_int pos;
+ int argc = mrb_get_args(mrb, "S|i", &sub, &pos);
+ mrb_int len = RSTRING_CHAR_LEN(str);
- if (mrb_get_args(mrb, "S|i", &sub, &pos) == 1) {
+ if (argc == 1) {
pos = len;
}
else {
@@ -2828,16 +2830,18 @@ static mrb_value
mrb_str_byteslice(mrb_state *mrb, mrb_value str)
{
mrb_value a1;
- mrb_int str_len = RSTRING_LEN(str), beg, len;
+ mrb_int str_len, beg, len;
mrb_bool empty = TRUE;
len = mrb_get_argc(mrb);
switch (len) {
case 2:
mrb_get_args(mrb, "ii", &beg, &len);
+ str_len = RSTRING_LEN(str);
break;
case 1:
a1 = mrb_get_arg1(mrb);
+ str_len = RSTRING_LEN(str);
if (mrb_range_p(a1)) {
if (mrb_range_beg_len(mrb, a1, &beg, &len, str_len, TRUE) != MRB_RANGE_OK) {
return mrb_nil_value();

Get object properties after `mrb_get_args()`

ref. #5613

I checked with Valgrind, and the methods that can cause use-after-free are `Array#rotate`, `Array#rotate!`, and `String#byteslice`.
Since `String#rindex` uses `RSTRING_LEN()` indirectly inside the function, no reference to the out-of-bounds range is generated.