trouble with pointers dot c

pointers.c

#include <stdio.h>
#include <stdlib.h>

#define LINE_LENGTH 1024

int get_line_with_prefix_from_file(const char* prefix, FILE* file, char* result_buf) {
    char line_buf[LINE_LENGTH];
    int matches = 0;

    while (fgets(line_buf, LINE_LENGTH, file)) {
        // segfaults here
        matches = sscanf(line_buf, prefix, result_buf);

        // if we actually found something
        if (matches == 1) {
            return 1;
        }
    }

    return 0;
}

int main(int argc, const char* argv[]) {
    FILE *cpuinfo;
    char result_buf[LINE_LENGTH];

    // normally check we got a valid pointer, but not in GIST MODE
    cpuinfo = fopen("/proc/cpuinfo", "r");

    int success = get_line_with_prefix_from_file("model name%[^:] %s", cpuinfo, result_buf);

    if (success) {
        printf("processor type: %s", result_buf);
    }

    fclose(cpuinfo);

    return 0;
}