heap-buffer-overflow at jsi_utf_tocase src/jsiString.c:396

[kvenux]

Build environment:

Ubuntu 16.04
gcc 5.4.0
version: c95c897
build command:
export JSI__SANITIZE=1
make
test command: ./jsish poc

Target device:

Desktop Linux

POC

jsish-1021-000094.txt

Description

Below is the ASAN outputs.

=================================================================
==111446==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60200000c2f2 at pc 0x0000004cb802 bp 0x7ffe11e8b650 sp 0x7ffe11e8b640
READ of size 1 at 0x60200000c2f2 thread T0
#0 0x4cb801 in jsi_utf_tocase src/jsiString.c:396
#1 0x4cc578 in StringToLowerCaseCmd src/jsiString.c:428
#2 0x4a82f8 in jsi_FuncCallSub src/jsiProto.c:244
#3 0x72059a in jsiFunctionSubCall src/jsiEval.c:790
#4 0x72059a in jsiEvalFunction src/jsiEval.c:825
#5 0x72059a in jsiEvalCodeSub src/jsiEval.c:1250
#6 0x73335f in jsi_evalcode src/jsiEval.c:2190
#7 0x4a93bd in jsi_FuncCallSub src/jsiProto.c:220
#8 0x720371 in jsiFunctionSubCall src/jsiEval.c:790
#9 0x720371 in jsiEvalFunction src/jsiEval.c:825
#10 0x720371 in jsiEvalCodeSub src/jsiEval.c:1250
#11 0x73335f in jsi_evalcode src/jsiEval.c:2190
#12 0x4a93bd in jsi_FuncCallSub src/jsiProto.c:220
#13 0x720371 in jsiFunctionSubCall src/jsiEval.c:790
#14 0x720371 in jsiEvalFunction src/jsiEval.c:825
#15 0x720371 in jsiEvalCodeSub src/jsiEval.c:1250
#16 0x73335f in jsi_evalcode src/jsiEval.c:2190
#17 0x736037 in jsi_evalStrFile src/jsiEval.c:2496
#18 0x47e0ee in Jsi_Main src/jsiInterp.c:917
#19 0x90be3e in jsi_main src/main.c:44
#20 0x7f09e6f8b83f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
#21 0x418238 in _start (/home/keven/Fuzzing/jsish-1023/jsish+0x418238)

0x60200000c2f2 is located 0 bytes to the right of 2-byte region [0x60200000c2f0,0x60200000c2f2)
allocated by thread T0 here:
#0 0x7f09e7af7602 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
#1 0x4825c2 in Jsi_Malloc src/jsiUtils.c:52

SUMMARY: AddressSanitizer: heap-buffer-overflow src/jsiString.c:396 jsi_utf_tocase
Shadow bytes around the buggy address:
0x0c047fff9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9810: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9820: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9830: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9840: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9850: fa fa fa fa fa fa fa fa fa fa fa fa fa fa[02]fa
0x0c047fff9860: fa fa fd fa fa fa fd fa fa fa fd fd fa fa fd fa
0x0c047fff9870: fa fa fd fa fa fa fd fd fa fa fd fd fa fa fd fa
0x0c047fff9880: fa fa fd fa fa fa fd fa fa fa fd fa fa fa fd fa
0x0c047fff9890: fa fa fd fd fa fa fd fa fa fa fd fa fa fa fd fa
0x0c047fff98a0: fa fa 00 00 fa fa 04 fa fa fa 04 fa fa fa fd 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
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
==111446==ABORTING