Commit 9cf448c2 authored by Shreyansh Chouhan's avatar Shreyansh Chouhan Committed by David S. Miller
Browse files

ip6_gre: add validation for csum_start 



Validate csum_start in gre_handle_offloads before we call _gre_xmit so
that we do not crash later when the csum_start value is used in the
lco_csum function call.

This patch deals with ipv6 code.

Fixes: Fixes: b05229f4 ("gre6: Cleanup GREv6 transmit path, call common
GRE functions")
Reported-by: default avatar <syzbot+ff8e1b9f2f36481e2efc@syzkaller.appspotmail.com>
Signed-off-by: default avatarShreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1d011c48

net/ipv6/ip6_gre.c

+2 −0
Original line number Diff line number Diff line
@@ -629,6 +629,8 @@ static int gre_rcv(struct sk_buff *skb) 


static int gre_handle_offloads(struct sk_buff *skb, bool csum)

{

	if (csum && skb_checksum_start(skb) < skb->data)

		return -EINVAL;

	return iptunnel_handle_offloads(skb,

					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);

}