Re: [PATCH net v4] rds: filter RDS_INFO_* getsockopt by caller's netns

[Maoyi Xie]

Hi Simon,

Confirmed. net/rds/bind.c writes rs_bound_addr at lines 123,
138, and 160 without taking rds_sock_lock. The race is real,
and the len=0 path you described reaches the NULL iter->pages.

v5 caps the second pass at cnt in all four handlers
(rds_sock_info, rds6_sock_info, rds_tcp_tc_info,
rds6_tcp_tc_info):

    unsigned int copied = 0;
    list_for_each_entry(rs, &rds_sock_list, rs_item) {
        if (copied >= cnt)
            break;
        if (!net_eq(sock_net(rds_rs_to_sk(rs)), net))
            continue;
        if (!ipv6_addr_v4mapped(&rs->rs_bound_addr))
            continue;
        ...
        rds_info_copy(iter, &sinfo, sizeof(sinfo));
        copied++;
    }

Sent as v5 in a separate mail.

Thanks,
Maoyi Xie