From b678aa578c9e400429e027269e8de2783e5e73ce Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Fri, 21 Oct 2016 18:28:25 +0900 Subject: [PATCH 1/1] ipv6: do not increment mac header when it's unset Otherwise we'll overflow the integer. This occurs when layer 3 tunneled packets are handed off to the IPv6 layer. Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- net/ipv6/reassembly.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 2160d5d009cb..3815e8505ed2 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -456,7 +456,8 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; memmove(head->head + sizeof(struct frag_hdr), head->head, (head->data - head->head) - sizeof(struct frag_hdr)); - head->mac_header += sizeof(struct frag_hdr); + if (skb_mac_header_was_set(head)) + head->mac_header += sizeof(struct frag_hdr); head->network_header += sizeof(struct frag_hdr); skb_reset_transport_header(head); -- 2.20.1