From: Greg Kroah-Hartman <gre...@linuxfoundation.org>
From: Balazs Nemeth <bnem...@redhat.com>
commit d348ede32e99d3a04863e9f9b28d224456118c27 upstream.
A packet with skb_inner_network_header(skb) == skb_network_header(skb)
and ETH_P_MPLS_UC will prevent mpls_gso_segment from pulling any headers
from the packet. Subsequently, the call to skb_mac_gso_segment will
again call mpls_gso_segment with the same packet leading to an infinite
loop. In addition, ensure that the header length is a multiple of four,
which should hold irrespective of the number of stacked labels.
Signed-off-by: Balazs Nemeth <bnem...@redhat.com>
Acked-by: Willem de Bruijn <will...@google.com>
Reviewed-by: David Ahern <dsah...@kernel.org>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/mpls/mpls_gso.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -14,6 +14,7 @@
#include <linux/netdev_features.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
+#include <net/mpls.h>
static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
netdev_features_t features)
@@ -27,6 +28,8 @@ static struct sk_buff *mpls_gso_segment(
skb_reset_network_header(skb);
mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb);
+ if (unlikely(!mpls_hlen || mpls_hlen % MPLS_HLEN))
+ goto out;
if (unlikely(!pskb_may_pull(skb, mpls_hlen)))
goto out;
