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authorJiri Benc <jbenc@redhat.com>2014-08-21 21:33:44 +0200
committerDavid S. Miller <davem@davemloft.net>2014-08-22 11:24:04 -0700
commit2ba5af42a7b59ef01f9081234d8855140738defd (patch)
treef37c603b7da12aa2a07db4094ea6b524a89d2844 /net
parent793c3b4000a1ef611ae7e5c89bd2a9c6b776cb5e (diff)
openvswitch: fix panic with multiple vlan headers
When there are multiple vlan headers present in a received frame, the first one is put into vlan_tci and protocol is set to ETH_P_8021Q. Anything in the skb beyond the VLAN TPID may be still non-linear, including the inner TCI and ethertype. While ovs_flow_extract takes care of IP and IPv6 headers, it does nothing with ETH_P_8021Q. Later, if OVS_ACTION_ATTR_POP_VLAN is executed, __pop_vlan_tci pulls the next vlan header into vlan_tci. This leads to two things: 1. Part of the resulting ethernet header is in the non-linear part of the skb. When eth_type_trans is called later as the result of OVS_ACTION_ATTR_OUTPUT, kernel BUGs in __skb_pull. Also, __pop_vlan_tci is in fact accessing random data when it reads past the TPID. 2. network_header points into the ethernet header instead of behind it. mac_len is set to a wrong value (10), too. Reported-by: Yulong Pei <ypei@redhat.com> Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/openvswitch/actions.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index fe5cda0deb39..5231652a95d9 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -42,6 +42,9 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
static int make_writable(struct sk_buff *skb, int write_len)
{
+ if (!pskb_may_pull(skb, write_len))
+ return -ENOMEM;
+
if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
return 0;
@@ -70,6 +73,8 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
vlan_set_encap_proto(skb, vhdr);
skb->mac_header += VLAN_HLEN;
+ if (skb_network_offset(skb) < ETH_HLEN)
+ skb_set_network_header(skb, ETH_HLEN);
skb_reset_mac_len(skb);
return 0;