• I
    netfilter: Zero the tuple in nfnl_cthelper_parse_tuple() · 78146572
    Ian Wilson 提交于
    nfnl_cthelper_parse_tuple() is called from nfnl_cthelper_new(),
    nfnl_cthelper_get() and nfnl_cthelper_del().  In each case they pass
    a pointer to an nf_conntrack_tuple data structure local variable:
    
        struct nf_conntrack_tuple tuple;
        ...
        ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
    
    The problem is that this local variable is not initialized, and
    nfnl_cthelper_parse_tuple() only initializes two fields: src.l3num and
    dst.protonum.  This leaves all other fields with undefined values
    based on whatever is on the stack:
    
        tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
        tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
    
    The symptom observed was that when the rpc and tns helpers were added
    then traffic to port 1536 was being sent to user-space.
    Signed-off-by: NIan Wilson <iwilson@brocade.com>
    Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
    78146572
nfnetlink_cthelper.c 16.6 KB