| From 1f63cfeb72e5158768de1f70b046e5803a3d5437 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 14 Sep 2018 12:26:47 +0800 |
| Subject: ip_gre: fix parsing gre header in ipgre_err |
| |
| From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> |
| |
| [ Upstream commit b0350d51f001e6edc13ee4f253b98b50b05dd401 ] |
| |
| gre_parse_header stops parsing when csum_err is encountered, which means |
| tpi->key is undefined and ip_tunnel_lookup will return NULL improperly. |
| |
| This patch introduce a NULL pointer as csum_err parameter. Even when |
| csum_err is encountered, it won't return error and continue parsing gre |
| header as expected. |
| |
| Fixes: 9f57c67c379d ("gre: Remove support for sharing GRE protocol hook.") |
| Reported-by: Jiri Benc <jbenc@redhat.com> |
| Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/ipv4/gre_demux.c | 7 ++++--- |
| net/ipv4/ip_gre.c | 9 +++------ |
| 2 files changed, 7 insertions(+), 9 deletions(-) |
| |
| diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c |
| index f21ea6125fc2d..511b32ea25331 100644 |
| --- a/net/ipv4/gre_demux.c |
| +++ b/net/ipv4/gre_demux.c |
| @@ -87,13 +87,14 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, |
| |
| options = (__be32 *)(greh + 1); |
| if (greh->flags & GRE_CSUM) { |
| - if (skb_checksum_simple_validate(skb)) { |
| + if (!skb_checksum_simple_validate(skb)) { |
| + skb_checksum_try_convert(skb, IPPROTO_GRE, 0, |
| + null_compute_pseudo); |
| + } else if (csum_err) { |
| *csum_err = true; |
| return -EINVAL; |
| } |
| |
| - skb_checksum_try_convert(skb, IPPROTO_GRE, 0, |
| - null_compute_pseudo); |
| options++; |
| } |
| |
| diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c |
| index 758a0f86d499f..681276111310b 100644 |
| --- a/net/ipv4/ip_gre.c |
| +++ b/net/ipv4/ip_gre.c |
| @@ -232,13 +232,10 @@ static void gre_err(struct sk_buff *skb, u32 info) |
| const int type = icmp_hdr(skb)->type; |
| const int code = icmp_hdr(skb)->code; |
| struct tnl_ptk_info tpi; |
| - bool csum_err = false; |
| |
| - if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), |
| - iph->ihl * 4) < 0) { |
| - if (!csum_err) /* ignore csum errors. */ |
| - return; |
| - } |
| + if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), |
| + iph->ihl * 4) < 0) |
| + return; |
| |
| if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { |
| ipv4_update_pmtu(skb, dev_net(skb->dev), info, |
| -- |
| 2.20.1 |
| |