diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index 43de3a03ee766796fca787aec67b2efa1cc3d614..3e4ddcb7e78142242268a8fce7a30401677557a9 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -526,9 +526,13 @@ nfqnl_set_mode(struct nfqnl_instance *queue, case NFQNL_COPY_PACKET: queue->copy_mode = mode; - /* we're using struct nlattr which has 16bit nla_len */ - if (range > 0xffff) - queue->copy_range = 0xffff; + /* We're using struct nlattr which has 16bit nla_len. Note that + * nla_len includes the header length. Thus, the maximum packet + * length that we support is 65531 bytes. We send truncated + * packets if the specified length is larger than that. + */ + if (range > 0xffff - NLA_HDRLEN) + queue->copy_range = 0xffff - NLA_HDRLEN; else queue->copy_range = range; break;