[PATCH 4.9 20/39] ip6_gre: only increase err_count for some certain type icmpv6 in ip6gre_err

From: Greg Kroah-Hartman
Date: Thu Nov 16 2017 - 13:02:32 EST


4.9-stable review patch. If anyone has any objections, please let me know.

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

From: Xin Long <lucien.xin@xxxxxxxxx>


[ Upstream commit f8d20b46ce55cf40afb30dcef6d9288f7ef46d9b ]

The similar fix in patch 'ipip: only increase err_count for some
certain type icmp in ipip_err' is needed for ip6gre_err.

In Jianlin's case, udp netperf broke even when receiving a TooBig
icmpv6 packet.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reported-by: Jianlin Shi <jishi@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_gre.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -408,13 +408,16 @@ static void ip6gre_err(struct sk_buff *s
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
t->parms.name);
- break;
+ if (code != ICMPV6_PORT_UNREACH)
+ break;
+ return;
case ICMPV6_TIME_EXCEED:
if (code == ICMPV6_EXC_HOPLIMIT) {
net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
t->parms.name);
+ break;
}
- break;
+ return;
case ICMPV6_PARAMPROB:
teli = 0;
if (code == ICMPV6_HDR_FIELD)
@@ -430,7 +433,7 @@ static void ip6gre_err(struct sk_buff *s
net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
t->parms.name);
}
- break;
+ return;
case ICMPV6_PKT_TOOBIG:
mtu = be32_to_cpu(info) - offset - t->tun_hlen;
if (t->dev->type == ARPHRD_ETHER)
@@ -438,7 +441,7 @@ static void ip6gre_err(struct sk_buff *s
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
t->dev->mtu = mtu;
- break;
+ return;
}

if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))