SEGV (/usr/local/bin/mjs+0xe533e)

[hope-fly]

mJS revision

Commit: b1b6eac

Version:

Build platform

Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)

Build steps

vim Makefile
DOCKER_GCC=gcc
$(DOCKER_GCC) $(CFLAGS) $(TOP_MJS_SOURCES) $(TOP_COMMON_SOURCES) -o $(PROG)
# save the makefile then make
make

Test case

poc.js

```javascript
isNaN(--isNaN) !== true

if (isNaN(-function () { return 1 }) !== true) {
    $ERROR('#Error' + (-function () { return 1 }));
}
```

Execution steps & Output

$ ./mjs/build/mjs poc.js
ASAN:DEADLYSIGNAL
=================================================================
==36318==ERROR: AddressSanitizer: SEGV on unknown address 0x559b7cd412cc (pc 0x559b7cd4133f bp 0x000000000043 sp 0x7fff0319d2b8 T0)
==36318==The signal is caused by a WRITE memory access.
    #0 0x559b7cd4133e  (/usr/local/bin/mjs+0xe533e)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/usr/local/bin/mjs+0xe533e)
==36318==ABORTING

Credits: Found by OWL337 team.