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| author | Jiri Benc <jbenc@redhat.com> | 2014-08-21 21:33:44 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-10-17 09:43:13 +0200 |
| commit | ddc07cc3af29477df691ed5d87a52c867c0f9b23 (patch) | |
| tree | 73a17d4c7380a303eacdc7cd218ab9296f46183f /net/openvswitch | |
| parent | c7c834d3b698e1fbac1b4116ae2cfd4b1011d44b (diff) | |
| download | lwn-ddc07cc3af29477df691ed5d87a52c867c0f9b23.tar.gz lwn-ddc07cc3af29477df691ed5d87a52c867c0f9b23.zip | |
openvswitch: fix panic with multiple vlan headers
[ Upstream commit 2ba5af42a7b59ef01f9081234d8855140738defd ]
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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net/openvswitch')
| -rw-r--r-- | net/openvswitch/actions.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index 65cfaa816075..07c4ae308bad 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; |