Commit 43c13605 authored by Davide Caratti's avatar Davide Caratti Committed by Jakub Kicinski
Browse files

net: openvswitch: ensure LSE is pullable before reading it 



when openvswitch is configured to mangle the LSE, the current value is
read from the packet dereferencing 4 bytes at mpls_hdr(): ensure that
the label is contained in the skb "linear" area.

Found by code inspection.

Fixes: d27cf5c5 ("net: core: add MPLS update core helper and use in OvS")
Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/aa099f245d93218b84b5c056b67b6058ccf81a66.1606987185.git.dcaratti@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 13de4ed9

net/openvswitch/actions.c

+3 −0
Original line number Diff line number Diff line
@@ -199,6 +199,9 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key, 
	__be32 lse;

	int err;



	if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN))

		return -ENOMEM;



	stack = mpls_hdr(skb);

	lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);

	err = skb_mpls_update_lse(skb, lse);