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ip_gre: fix parsing gre header in ipgre_err

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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: 9f57c67c37 ("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>
This commit is contained in:
Haishuang Yan 2018-09-14 12:26:47 +08:00 committed by David S. Miller
parent 21e65923ab
commit b0350d51f0
2 changed files with 7 additions and 9 deletions
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7
net/ipv4/gre_demux.c
View File

@ -86,13 +86,14 @@ 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++;
}

9
net/ipv4/ip_gre.c
View File

@ -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,