| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 009/119] net/ipv6: Fix CALIPSO causing GPF with datagram support | Date | Mon, 12 Jun 2017 17:24:31 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Richard Haines <richard_c_haines@btinternet.com>
[ Upstream commit e3ebdb20fddacded2740a333ff66781e0d28b05c ]
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 <richard_c_haines@btinternet.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv6/calipso.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/ipv6/calipso.c +++ b/net/ipv6/calipso.c @@ -1319,7 +1319,7 @@ static int calipso_skbuff_setattr(struct 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 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 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);
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