geneve: avoid use-after-free of skb->data
geneve{,6}_build_skb can end up doing a pskb_expand_head(), which
makes the ip_hdr(skb) reference we stashed earlier stale. Since it's
only needed as an argument to ip_tunnel_ecn_encap(), move this
directly in the function call.
Fixes: 08399efc6319 ("geneve: ensure ECN info is handled properly in all tx/rx paths")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 42edd7b..8b4822a 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -859,7 +859,6 @@
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs4;
struct rtable *rt = NULL;
- const struct iphdr *iip; /* interior IP header */
int err = -EINVAL;
struct flowi4 fl4;
__u8 tos, ttl;
@@ -890,8 +889,6 @@
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
skb_reset_mac_header(skb);
- iip = ip_hdr(skb);
-
if (info) {
const struct ip_tunnel_key *key = &info->key;
u8 *opts = NULL;
@@ -911,7 +908,7 @@
if (unlikely(err))
goto tx_error;
- tos = ip_tunnel_ecn_encap(key->tos, iip, skb);
+ tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
ttl = key->ttl;
df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
} else {
@@ -920,7 +917,7 @@
if (unlikely(err))
goto tx_error;
- tos = ip_tunnel_ecn_encap(fl4.flowi4_tos, iip, skb);
+ tos = ip_tunnel_ecn_encap(fl4.flowi4_tos, ip_hdr(skb), skb);
ttl = geneve->ttl;
if (!ttl && IN_MULTICAST(ntohl(fl4.daddr)))
ttl = 1;
@@ -952,7 +949,6 @@
{
struct geneve_dev *geneve = netdev_priv(dev);
struct dst_entry *dst = NULL;
- const struct iphdr *iip; /* interior IP header */
struct geneve_sock *gs6;
int err = -EINVAL;
struct flowi6 fl6;
@@ -982,8 +978,6 @@
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
skb_reset_mac_header(skb);
- iip = ip_hdr(skb);
-
if (info) {
const struct ip_tunnel_key *key = &info->key;
u8 *opts = NULL;
@@ -1004,7 +998,7 @@
if (unlikely(err))
goto tx_error;
- prio = ip_tunnel_ecn_encap(key->tos, iip, skb);
+ prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
ttl = key->ttl;
label = info->key.label;
} else {
@@ -1014,7 +1008,7 @@
goto tx_error;
prio = ip_tunnel_ecn_encap(ip6_tclass(fl6.flowlabel),
- iip, skb);
+ ip_hdr(skb), skb);
ttl = geneve->ttl;
if (!ttl && ipv6_addr_is_multicast(&fl6.daddr))
ttl = 1;