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authorBalazs Nemeth <bnemeth@redhat.com>2021-03-09 12:31:01 +0100
committerDavid S. Miller <davem@davemloft.net>2021-03-09 16:12:20 -0800
commitd348ede32e99d3a04863e9f9b28d224456118c27 (patch)
treeaa561ac181147df2e9c5b52ed67706e2e26ba9c9 /net/mpls
parent924a9bc362a5223cd448ca08c3dde21235adc310 (diff)
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net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0
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 <bnemeth@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mpls')
-rw-r--r--net/mpls/mpls_gso.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index b1690149b6fa..1482259de9b5 100644
--- 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(struct sk_buff *skb,
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;