erspan: fix version 1 check in gre_parse_header()

Both version 0 and version 1 use ETH_P_ERSPAN, but version 0 does not
have an erspan header. So the check in gre_parse_header() is wrong,
we have to distinguish version 1 from version 0.

We can just check the gre header length like is_erspan_type1().

Fixes: cb73ee40b1 ("net: ip_gre: use erspan key field for tunnel lookup")
Reported-by: syzbot+f583ce3d4ddf9836b27a@syzkaller.appspotmail.com
Cc: William Tu <u9012063@gmail.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2020-12-26 15:44:53 -08:00 коммит произвёл David S. Miller
Родитель 5ede3ada3d
Коммит 085c7c4e1c
1 изменённых файлов: 1 добавлений и 1 удалений

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@ -128,7 +128,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
* to 0 and sets the configured key in the
* inner erspan header field
*/
if (greh->protocol == htons(ETH_P_ERSPAN) ||
if ((greh->protocol == htons(ETH_P_ERSPAN) && hdr_len != 4) ||
greh->protocol == htons(ETH_P_ERSPAN2)) {
struct erspan_base_hdr *ershdr;