From e3ebdb20fddacded2740a333ff66781e0d28b05c Mon Sep 17 00:00:00 2001 From: Richard Haines Date: Mon, 5 Jun 2017 16:44:40 +0100 Subject: net/ipv6: Fix CALIPSO causing GPF with datagram support When using CALIPSO with IPPROTO_UDP it is possible to trigger a GPF as the IP header may have moved. Also update the payload length after adding the CALIPSO option. Signed-off-by: Richard Haines Acked-by: Paul Moore Signed-off-by: Huw Davies Signed-off-by: David S. Miller --- net/ipv6/calipso.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net/ipv6/calipso.c') diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c index 37ac9de713c6..8d772fea1dde 100644 --- a/net/ipv6/calipso.c +++ b/net/ipv6/calipso.c @@ -1319,7 +1319,7 @@ static int calipso_skbuff_setattr(struct sk_buff *skb, struct ipv6hdr *ip6_hdr; struct ipv6_opt_hdr *hop; unsigned char buf[CALIPSO_MAX_BUFFER]; - int len_delta, new_end, pad; + int len_delta, new_end, pad, payload; unsigned int start, end; ip6_hdr = ipv6_hdr(skb); @@ -1346,6 +1346,8 @@ static int calipso_skbuff_setattr(struct sk_buff *skb, if (ret_val < 0) return ret_val; + ip6_hdr = ipv6_hdr(skb); /* Reset as skb_cow() may have moved it */ + if (len_delta) { if (len_delta > 0) skb_push(skb, len_delta); @@ -1355,6 +1357,8 @@ static int calipso_skbuff_setattr(struct sk_buff *skb, sizeof(*ip6_hdr) + start); skb_reset_network_header(skb); ip6_hdr = ipv6_hdr(skb); + payload = ntohs(ip6_hdr->payload_len); + ip6_hdr->payload_len = htons(payload + len_delta); } hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1); -- cgit