From 15aaf7e76567ab59307bfd68aa0be41abaa5b003 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Mon, 25 Mar 2013 20:19:59 +0000 Subject: net_sched: better precise estimation on packet length for untrusted packets [ Upstream commit 15e5a030716468dce4032fa0f398d840fa2756f6 ] gso_segs were reset to zero when kernel receive packets from untrusted source. But we use this zero value to estimate precise packet len which is wrong. So this patch tries to estimate the correct gso_segs value before using it in qdisc_pkt_len_init(). Signed-off-by: Jason Wang Cc: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 9a278e930426..c9eb9e6be87f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2592,6 +2592,7 @@ static void qdisc_pkt_len_init(struct sk_buff *skb) */ if (shinfo->gso_size) { unsigned int hdr_len; + u16 gso_segs = shinfo->gso_segs; /* mac layer + network layer */ hdr_len = skb_transport_header(skb) - skb_mac_header(skb); @@ -2601,7 +2602,12 @@ static void qdisc_pkt_len_init(struct sk_buff *skb) hdr_len += tcp_hdrlen(skb); else hdr_len += sizeof(struct udphdr); - qdisc_skb_cb(skb)->pkt_len += (shinfo->gso_segs - 1) * hdr_len; + + if (shinfo->gso_type & SKB_GSO_DODGY) + gso_segs = DIV_ROUND_UP(skb->len - hdr_len, + shinfo->gso_size); + + qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; } } -- cgit v1.2.3