Description of problem:

getgrouplist does not return groups whose lines in /etc/group are longer than 1024 characters.

It appears that _nss_files_parse_grent decides to return 0 after the input buffer has been resized to be large enough.

Version-Release number of selected component (if applicable):


glibc-2.14-5.x86_64

How reproducible:

Add a root  to a group with a line in /etc/groups that is longer than 1024 characters.

Observer the group is not listed with:

#define _BSD_SOURCE 1
#include <stdio.h>
#include <sys/types.h>
#include <grp.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

void *xmalloc(size_t size)
{
        void *ptr;
        ptr = malloc(size);
        if (!ptr) {
                fprintf(stderr, "malloc failed:%s\n",
                        strerror(errno));
                exit(1);
        }
        memset(ptr, '\0', size);
        return ptr;
}

int main(int argc, char **argv)
{
        {
                char *user_name = "root";
                gid_t user_gid = 0;
                gid_t *grouplist, grouptmp;
                int n_groups, i;
                n_groups = 1;
                if (getgrouplist(user_name, user_gid, &grouptmp, &n_groups) == -1) {
                        grouplist = (gid_t *)xmalloc(sizeof(gid_t) * (n_groups + 1));
                        if (getgrouplist(user_name, user_gid, grouplist, &n_groups) > 0) {
                                for (i = 0; i < n_groups; i++) {
                                        printf("%u\n", grouplist[i]);
                                }
                        }
                        free(grouplist);
                }
        }
        return 0;
}