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| author | Eric Dumazet <edumazet@google.com> | 2017-01-24 03:43:05 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-24 22:53:24 +0300 |
| commit | 21b995a9cb093fff33ec91d7cb3822b882a90a1e (patch) | |
| tree | e7f434a5d9961bd65a461dffe8c7a010dd74ecca | |
| parent | d0fa28f00052391b5df328f502fbbdd4444938b7 (diff) | |
| download | linux-21b995a9cb093fff33ec91d7cb3822b882a90a1e.tar.xz | |
ip6_tunnel: must reload ipv6h in ip6ip6_tnl_xmit()
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>
| -rw-r--r-- | net/ipv6/ip6_gre.c | 3 | ||||
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 75b6108234dd..558631860d91 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -582,6 +582,9 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev) 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]; diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 753d6d0860fb..02923f956ac8 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1303,6 +1303,8 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 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; |