[LU-11030] Uninitialized variable use in fld_update_from_controller

Fri, 18 May 2018 00:17:16 +0000

In looks like we can use index variable without initialization in fld_update_from_controller:

        __u32                     index;
...
        rc = fld_name_to_index(fld->lsf_name, &index);
        if (rc < 0)
                RETURN(rc);

        /* No need update fldb for MDT0 */
        if (index == 0)
                RETURN(0);

Now if we look into fld_name_to_index() it looks ok:

int fld_name_to_index(const char *name, __u32 *index)
{
        char *dash;
        int rc;
        ENTRY;

        CDEBUG(D_INFO, "get index from %s\n", name);
        dash = strrchr(name, '-');
        if (dash == NULL)
                RETURN(-EINVAL);
        dash++;
        rc = target_name2index(dash, index, NULL);
        RETURN(rc);
}

As in we return negative value to caller if the index is not updated.

But if we actually look inside target_name2index, we can see:

        if (strncmp(dash, "MDT", 3) == 0)
                rc = LDD_F_SV_TYPE_MDT;
        else if (strncmp(dash, "OST", 3) == 0)
                rc = LDD_F_SV_TYPE_OST;
        else
                return -EINVAL;

        dash += 3;

        if (strncmp(dash, "all", 3) == 0) {
                if (endptr != NULL)
                        *endptr = dash + 3;
                return rc | LDD_F_SV_ALL;
        }

so if we have 'all' literal after the dash - the index is not updated and we don't return an error.

This needs to be handled one way or another.

Whamcloud Community JIRA

[LU-11030] Uninitialized variable use in fld_update_from_controller