From: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 0b87558f265eb..9d5db4e40b2a9 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
