linux-security-module.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] net/ipv6: Fix CALIPSO causing GPF with datagram support
@ 2017-06-05 15:44 Richard Haines
  2017-06-05 15:55 ` Paul Moore
  2017-06-06 19:19 ` David Miller
  0 siblings, 2 replies; 5+ messages in thread
From: Richard Haines @ 2017-06-05 15:44 UTC (permalink / raw)
  To: linux-security-module

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>
---
 net/ipv6/calipso.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index 37ac9de..8d772fe 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);
-- 
2.9.4

--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2017-06-06 19:19 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-06-05 15:44 [PATCH] net/ipv6: Fix CALIPSO causing GPF with datagram support Richard Haines
2017-06-05 15:55 ` Paul Moore
2017-06-05 16:00   ` David Miller
2017-06-05 17:20   ` Huw Davies
2017-06-06 19:19 ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).