Commit 085c7c4e authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

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: cb73ee40 ("net: ip_gre: use erspan key field for tunnel lookup")
Reported-by: default avatar <syzbot+f583ce3d4ddf9836b27a@syzkaller.appspotmail.com>
Cc: William Tu <u9012063@gmail.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5ede3ada

net/ipv4/gre_demux.c

+1 −1
Original line number Diff line number Diff line
@@ -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;