Challenge: write a query to find this C NULL dereference

[catenacyber]

See OISF/suricata#11098

The code is basically :

static void AllocAndProcessStep2(SomeStruct *r, otherargs...) {
    // do not check r, and dereference it !!!
    if (r->somefield) {
        // do something
    }
}

static SomeStruct * AllocAndProcessStep1(someargs) {
    if (unlikelyButMayHappen(someargs)) {
        return NULL;
    } 
    SomeStruct * r = malloc(somesize);
    if (r == NULL) {
        return NULL;
    }
    // fill some r fields
    return r;
}

static SomeStruct * AllocAndProcess(someargs) {
    SomeStruct * r = AllocAndProcessStep1(someargs);
    // do not check r
    AllocAndProcessStep2(r, ...);
    return r;
}

static void Parent() {
    SomeStruct * r = AllocAndProcess(someargs);
    if (r == NULL) {
         // log error, etc...
        return;
    }
}

[catenacyber]

Trying something with #16524

Some interesting results, but most come from ignoring that allocations can fail...