Skip to content

Fix #254: Segmentation fault in Built-in APIs #258

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Fix #254: Segmentation fault in Built-in APIs #258

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
143 changes: 109 additions & 34 deletions mjs.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1630,6 +1630,9 @@ typedef struct stat cs_stat_t;
extern "C" {
#endif /* __cplusplus */

/* patch for the misused address access using built-in object (segmentation fault) */
static int64_t BUILT_IN_ADDRESS[18];

/*
* Log level; `LL_INFO` is the default. Use `cs_log_set_level()` to change it.
*/
Expand Down Expand Up @@ -7373,53 +7376,65 @@ static void mjs_s2o(struct mjs *mjs) {
void mjs_init_builtin(struct mjs *mjs, mjs_val_t obj) {
mjs_val_t v;

mjs_set(mjs, obj, "global", ~0, obj);

mjs_set(mjs, obj, "load", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_load));
mjs_set(mjs, obj, "print", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_print));
mjs_set(mjs, obj, "ffi", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_ffi_call));
mjs_set(mjs, obj, "ffi_cb_free", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_ffi_cb_free));
mjs_set(mjs, obj, "mkstr", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_mkstr));
mjs_set(mjs, obj, "getMJS", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_get_mjs));
mjs_set(mjs, obj, "die", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_die));
mjs_set(mjs, obj, "gc", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_do_gc));
mjs_set(mjs, obj, "chr", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_chr));
mjs_set(mjs, obj, "s2o", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_s2o));
BUILT_IN_ADDRESS[0] = obj;
mjs_set(mjs, obj, "global", ~0, BUILT_IN_ADDRESS[0]);
BUILT_IN_ADDRESS[1] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_load);
mjs_set(mjs, obj, "load", ~0, BUILT_IN_ADDRESS[1]);
BUILT_IN_ADDRESS[2] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_print);
mjs_set(mjs, obj, "print", ~0, BUILT_IN_ADDRESS[2]);
BUILT_IN_ADDRESS[3] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_ffi_call);
mjs_set(mjs, obj, "ffi", ~0, BUILT_IN_ADDRESS[3]);
BUILT_IN_ADDRESS[4] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_ffi_cb_free);
mjs_set(mjs, obj, "ffi_cb_free", ~0, BUILT_IN_ADDRESS[4]);
BUILT_IN_ADDRESS[5] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_mkstr);
mjs_set(mjs, obj, "mkstr", ~0, BUILT_IN_ADDRESS[5]);
BUILT_IN_ADDRESS[6] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_get_mjs);
mjs_set(mjs, obj, "getMJS", ~0, BUILT_IN_ADDRESS[6]);
BUILT_IN_ADDRESS[7] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_die);
mjs_set(mjs, obj, "die", ~0, BUILT_IN_ADDRESS[7]);
BUILT_IN_ADDRESS[8] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_do_gc);
mjs_set(mjs, obj, "gc", ~0, BUILT_IN_ADDRESS[8]);
BUILT_IN_ADDRESS[9] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_chr);
mjs_set(mjs, obj, "chr", ~0, BUILT_IN_ADDRESS[9]);
BUILT_IN_ADDRESS[10] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_s2o);
mjs_set(mjs, obj, "s2o", ~0, BUILT_IN_ADDRESS[10]);

/*
* Populate JSON.parse() and JSON.stringify()
*/
v = mjs_mk_object(mjs);
mjs_set(mjs, v, "stringify", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_json_stringify));
mjs_set(mjs, v, "parse", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_json_parse));
mjs_set(mjs, obj, "JSON", ~0, v);
BUILT_IN_ADDRESS[11] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_json_stringify);
mjs_set(mjs, v, "stringify", ~0, BUILT_IN_ADDRESS[11]);
BUILT_IN_ADDRESS[12] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_json_parse);
mjs_set(mjs, v, "parse", ~0, BUILT_IN_ADDRESS[12]);
BUILT_IN_ADDRESS[13] = v;
mjs_set(mjs, obj, "JSON", ~0, BUILT_IN_ADDRESS[13]);

/*
* Populate Object.create()
*/
v = mjs_mk_object(mjs);
mjs_set(mjs, v, "create", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_create_object));
mjs_set(mjs, obj, "Object", ~0, v);
BUILT_IN_ADDRESS[14] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_create_object);
mjs_set(mjs, v, "create", ~0, BUILT_IN_ADDRESS[14]);
BUILT_IN_ADDRESS[15] = v;
mjs_set(mjs, obj, "Object", ~0, BUILT_IN_ADDRESS[15]);

/*
* Populate numeric stuff
*/
mjs_set(mjs, obj, "NaN", ~0, MJS_TAG_NAN);
mjs_set(mjs, obj, "isNaN", ~0,
mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_isnan));
BUILT_IN_ADDRESS[16] = MJS_TAG_NAN;
mjs_set(mjs, obj, "NaN", ~0, BUILT_IN_ADDRESS[16]);
BUILT_IN_ADDRESS[17] = mjs_mk_foreign_func(mjs, (mjs_func_ptr_t) mjs_op_isnan);
mjs_set(mjs, obj, "isNaN", ~0, BUILT_IN_ADDRESS[17]);
}

int check_builtin_object(int64_t address) {
for(int i = 0; i < 18; i++){
if (BUILT_IN_ADDRESS[i] == address) {
return 1;
}
}
return 0;
}
#ifdef MJS_MODULE_LINES
#line 1 "src/mjs_conversion.c"
Expand Down Expand Up @@ -8228,21 +8243,37 @@ static void exec_expr(struct mjs *mjs, int op) {
case TOK_URSHIFT: {
mjs_val_t b = mjs_pop(mjs);
mjs_val_t a = mjs_pop(mjs);
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, do_op(mjs, a, b, op));
break;
}
case TOK_UNARY_MINUS: {
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_number(mjs, -a));
break;
}
case TOK_NOT: {
mjs_val_t val = mjs_pop(mjs);
if (check_builtin_object(val)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, !mjs_is_truthy(mjs, val)));
break;
}
case TOK_TILDA: {
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_number(mjs, (double) (~(int64_t) a)));
break;
}
Expand All @@ -8257,36 +8288,60 @@ static void exec_expr(struct mjs *mjs, int op) {
case TOK_EQ_EQ: {
mjs_val_t a = mjs_pop(mjs);
mjs_val_t b = mjs_pop(mjs);
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, check_equal(mjs, a, b)));
break;
}
case TOK_NE_NE: {
mjs_val_t a = mjs_pop(mjs);
mjs_val_t b = mjs_pop(mjs);
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, !check_equal(mjs, a, b)));
break;
}
case TOK_LT: {
double b = mjs_get_double(mjs, mjs_pop(mjs));
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, a < b));
break;
}
case TOK_GT: {
double b = mjs_get_double(mjs, mjs_pop(mjs));
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, a > b));
break;
}
case TOK_LE: {
double b = mjs_get_double(mjs, mjs_pop(mjs));
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, a <= b));
break;
}
case TOK_GE: {
double b = mjs_get_double(mjs, mjs_pop(mjs));
double a = mjs_get_double(mjs, mjs_pop(mjs));
if (check_builtin_object(a) || check_builtin_object(b)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_push(mjs, mjs_mk_boolean(mjs, a >= b));
break;
}
Expand All @@ -8296,7 +8351,7 @@ static void exec_expr(struct mjs *mjs, int op) {
mjs_val_t key = mjs_pop(mjs);
if (mjs_is_object(obj)) {
mjs_set_v(mjs, obj, key, val);
} else if (mjs_is_foreign(obj)) {
} else if (mjs_is_foreign(obj) && !check_builtin_object(obj)) {
/*
* We don't have setters, so in order to support properties which behave
* like setters, we have to parse key right here, instead of having real
Expand Down Expand Up @@ -8328,6 +8383,10 @@ static void exec_expr(struct mjs *mjs, int op) {
mjs_val_t key = mjs_pop(mjs);
if (mjs_is_object(obj) && mjs_is_string(key)) {
mjs_val_t v = mjs_get_v(mjs, obj, key);
if (check_builtin_object(v)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_val_t v1 = do_op(mjs, v, mjs_mk_number(mjs, 1), TOK_PLUS);
mjs_set_v(mjs, obj, key, v1);
mjs_push(mjs, v);
Expand All @@ -8341,6 +8400,10 @@ static void exec_expr(struct mjs *mjs, int op) {
mjs_val_t key = mjs_pop(mjs);
if (mjs_is_object(obj) && mjs_is_string(key)) {
mjs_val_t v = mjs_get_v(mjs, obj, key);
if (check_builtin_object(v)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
mjs_val_t v1 = do_op(mjs, v, mjs_mk_number(mjs, 1), TOK_MINUS);
mjs_set_v(mjs, obj, key, v1);
mjs_push(mjs, v);
Expand All @@ -8354,6 +8417,10 @@ static void exec_expr(struct mjs *mjs, int op) {
mjs_val_t key = mjs_pop(mjs);
if (mjs_is_object(obj) && mjs_is_string(key)) {
mjs_val_t v = mjs_get_v(mjs, obj, key);
if (check_builtin_object(v)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
v = do_op(mjs, v, mjs_mk_number(mjs, 1), TOK_MINUS);
mjs_set_v(mjs, obj, key, v);
mjs_push(mjs, v);
Expand All @@ -8367,6 +8434,10 @@ static void exec_expr(struct mjs *mjs, int op) {
mjs_val_t key = mjs_pop(mjs);
if (mjs_is_object(obj) && mjs_is_string(key)) {
mjs_val_t v = mjs_get_v(mjs, obj, key);
if (check_builtin_object(v)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
v = do_op(mjs, v, mjs_mk_number(mjs, 1), TOK_PLUS);
mjs_set_v(mjs, obj, key, v);
mjs_push(mjs, v);
Expand Down Expand Up @@ -8469,6 +8540,10 @@ static int getprop_builtin_foreign(struct mjs *mjs, mjs_val_t val,
mjs_prepend_errorf(mjs, MJS_TYPE_ERROR, "index must be a number");
} else {
uint8_t *ptr = (uint8_t *) mjs_get_ptr(mjs, val);
if (check_builtin_object(val)) {
printf("Operators cannot be used on built-in objects.\n");
exit(-1);
}
*res = mjs_mk_number(mjs, *(ptr + idx));
}
return 1;
Expand Down