diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index e42762023c27bd405783648f9503f165522e67f3..3551b6dc741905f59528d1eee49e0e9437974225 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -926,16 +926,19 @@ int ip_append_data(struct sock *sk, !(rt->dst.dev->features&NETIF_F_SG)) alloclen = mtu; else - alloclen = datalen + fragheaderlen; + alloclen = fraglen; /* The last fragment gets additional space at tail. * Note, with MSG_MORE we overallocate on fragments, * because we have no idea what fragment will be * the last. */ - if (datalen == length + fraggap) + if (datalen == length + fraggap) { alloclen += rt->dst.trailer_len; - + /* make sure mtu is not reached */ + if (datalen > mtu - fragheaderlen - rt->dst.trailer_len) + datalen -= ALIGN(rt->dst.trailer_len, 8); + } if (transhdrlen) { skb = sock_alloc_send_skb(sk, alloclen + hh_len + 15,