[4.9,009/119] net/ipv6: Fix CALIPSO causing GPF with datagram support
diff mbox series

Message ID 20170612152557.094890162@linuxfoundation.org
State New, archived
Headers show
Series
  • 4.9.32-stable review
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Commit Message

Greg Kroah-Hartman June 12, 2017, 3:24 p.m. UTC
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

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(-)

Patch
diff mbox series

--- 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);