lkml.org 
[lkml]   [2017]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 095/172] ip6_tunnel: must reload ipv6h in ip6ip6_tnl_xmit()
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Eric Dumazet <edumazet@google.com>


[ Upstream commit 21b995a9cb093fff33ec91d7cb3822b882a90a1e ]

Since ip6_tnl_parse_tlv_enc_lim() can call pskb_may_pull(),
we must reload any pointer that was related to skb->head
(or skb->data), or risk use after free.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/ip6_gre.c | 3 +++
net/ipv6/ip6_tunnel.c | 2 ++
2 files changed, 5 insertions(+)

--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -582,6 +582,9 @@ static inline int ip6gre_xmit_ipv6(struc
return -1;

offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
+ /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
+ ipv6h = ipv6_hdr(skb);
+
if (offset > 0) {
struct ipv6_tlv_tnl_enc_lim *tel;
tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1313,6 +1313,8 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, str
fl6.flowlabel = key->label;
} else {
offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
+ /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
+ ipv6h = ipv6_hdr(skb);
if (offset > 0) {
struct ipv6_tlv_tnl_enc_lim *tel;


\
 
 \ /
  Last update: 2017-07-03 16:28    [W:0.403 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site