Heap-buffer-overflow on pcre2_compile_8

Here is the code:

#include <cstdio>
#include <cstdlib>
#define PCRE2_CODE_UNIT_WIDTH 8
extern "C" {
    #include "config.h"
    #include "pcre2.h"
}

void* readFile (char* fileName, size_t& size) {
    FILE* filePtr = fopen(fileName, "r");
    fseek(filePtr, 0, SEEK_END);
    size = ftell(filePtr);
    fseek(filePtr, 0, SEEK_SET);
    void* ret = malloc(size);
    fread(ret, size, 1, filePtr);
    return ret;
}

int main (int argc, char** argv) {
    size_t size;
    void* data = readFile(argv[1], size);
    uint32_t option = 3758785504;
    int errorCode;
    size_t offset;
    pcre2_code_8* code = pcre2_compile_8(static_cast<unsigned char*>(data), size, option, &errorCode, &offset, nullptr);

    pcre2_code_free_8(code);
}

and here is the input file: testData.txt

AddressSanitizer reports like this:

=================================================================
==1384649==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61700000037a at pc 0x562e819fb648 bp 0x7fff3645fd90 sp 0x7fff3645fd88
READ of size 1 at 0x61700000037a thread T0
    #0 0x562e819fb647 in parse_regex pcre2/src/pcre2_compile.c:2804:3
    #1 0x562e819f393d in pcre2_compile_8 pcre2/src/pcre2_compile.c:10391:13
    #2 0x562e819d54e7 in main pcre2/TDDSuite_build/test.cc:25:26
    #3 0x7f2ca5c34082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
    #4 0x562e8191277d in _start (pcre2/TDDSuite_build/test.exe+0x6177d)

0x61700000037a is located 0 bytes to the right of 762-byte region [0x617000000080,0x61700000037a)
allocated by thread T0 here:
    #0 0x562e8199744e in malloc /home/frokaikan/Desktop/workspace/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:69:3
    #1 0x562e819d52ee in readFile(char*, unsigned long&) pcre2/TDDSuite_build/test.cc:14:17
    #2 0x562e819d547b in main pcre2/TDDSuite_build/test.cc:21:18
    #3 0x7f2ca5c34082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16

PCRE2Project / pcre2

Heap-buffer-overflow on pcre2_compile_8 #294