> ./mjs_asan -f mjs_heap-buffer-overflow_mjs13671
=================================================================
==23460==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60800000007d at pc 0x00000046b929 bp 0x7fff87d05cd0 sp 0x7fff87d05480
READ of size 94 at 0x60800000007d thread T0
#0 0x46b928 in __interceptor_strlen.part.0 /home/fzz/Desktop/STFGFuzz/LLVM/llvm/projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:372:5
#1 0x510fbf in mjs_mk_string /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:13671:35
#2 0x5328d2 in frozen_cb /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:11870:13
#3 0x5162ac in parse_string /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5884:9
#4 0x51597c in parse_value /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5970:7
#5 0x516bb3 in parse_array /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5936:9
#6 0x515a94 in parse_value /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5976:7
#7 0x503145 in doit /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:6058:10
#8 0x50077b in json_walk /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:6434:3
#9 0x532618 in mjs_json_parse /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:11963:14
#10 0x50a501 in mjs_op_json_parse /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:12012:5
#11 0x50e248 in mjs_execute /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9541:11
#12 0x50c4ce in mjs_exec_internal /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9758:5
#13 0x50c610 in mjs_exec_file /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9781:11
#14 0x50fe4f in main /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:12051:13
#15 0x7f5460494082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
#16 0x41c3cd in _start (/home/fzz/Desktop/STFGFuzz/Programs/mjs-issues-78/seeds_crash/mjs_asan+0x41c3cd)
0x60800000007d is located 0 bytes to the right of 93-byte region [0x608000000020,0x60800000007d)
allocated by thread T0 here:
#0 0x4c1f3f in malloc /home/fzz/Desktop/STFGFuzz/LLVM/llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x53287b in frozen_cb /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:11868:36
#2 0x5162ac in parse_string /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5884:9
#3 0x51597c in parse_value /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5970:7
#4 0x516bb3 in parse_array /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5936:9
#5 0x515a94 in parse_value /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:5976:7
#6 0x503145 in doit /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:6058:10
#7 0x50077b in json_walk /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:6434:3
#8 0x532618 in mjs_json_parse /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:11963:14
#9 0x50a501 in mjs_op_json_parse /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:12012:5
#10 0x50e248 in mjs_execute /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9541:11
#11 0x50c4ce in mjs_exec_internal /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9758:5
#12 0x50c610 in mjs_exec_file /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:9781:11
#13 0x50fe4f in main /root/compiler1804/aflgo_dataset/mjs-issues-78/mjs.c:12051:13
#14 0x7f5460494082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
SUMMARY: AddressSanitizer: heap-buffer-overflow /home/fzz/Desktop/STFGFuzz/LLVM/llvm/projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:372:5 in __interceptor_strlen.part.0
Shadow bytes around the buggy address:
0x0c107fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c107fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c107fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c107fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c107fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c107fff8000: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00[05]
0x0c107fff8010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c107fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c107fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c107fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c107fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==23460==ABORTING
Heap buffer overflow in mjs at function mjs_mk_string in mjs.c:13671.
Environment
Ubuntu 18.04, 64 bit
Steps to reproduce
Download poc: mjs_heap-buffer-overflow_mjs13671.zip
ASAN report