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authorJoe Stringer <joestringer@nicira.com>2015-10-25 20:21:48 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-27 19:32:14 -0700
commit74c16618137f1505b0a32dea3ec73a2ef6f8f842 (patch)
treea85b6a44ec0f5d8d7ae915968ee88250c323a292
parentc2229fe1430d4e1c70e36520229dd64a87802b20 (diff)
downloadlinux-stericsson-74c16618137f1505b0a32dea3ec73a2ef6f8f842.tar.gz
openvswitch: Fix double-free on ip_defrag() errors
If ip_defrag() returns an error other than -EINPROGRESS, then the skb is freed. When handle_fragments() passes this back up to do_execute_actions(), it will be freed again. Prevent this double free by never freeing the skb in do_execute_actions() for errors returned by ovs_ct_execute. Always free it in ovs_ct_execute() error paths instead. Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action") Reported-by: Florian Westphal <fw@strlen.de> Signed-off-by: Joe Stringer <joestringer@nicira.com> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/openvswitch/actions.c4
-rw-r--r--net/openvswitch/conntrack.c17
-rw-r--r--net/openvswitch/conntrack.h1
3 files changed, 16 insertions, 6 deletions
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 0bf0f406de52..dba635d086b2 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -1109,8 +1109,8 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
nla_data(a));
/* Hide stolen IP fragments from user space. */
- if (err == -EINPROGRESS)
- return 0;
+ if (err)
+ return err == -EINPROGRESS ? 0 : err;
break;
}
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index a5ec34f8502f..b5dcc0abde66 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -293,6 +293,9 @@ static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
return helper->help(skb, protoff, ct, ctinfo);
}
+/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
+ * value if 'skb' is freed.
+ */
static int handle_fragments(struct net *net, struct sw_flow_key *key,
u16 zone, struct sk_buff *skb)
{
@@ -308,8 +311,8 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key,
return err;
ovs_cb.mru = IPCB(skb)->frag_max_size;
- } else if (key->eth.type == htons(ETH_P_IPV6)) {
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
+ } else if (key->eth.type == htons(ETH_P_IPV6)) {
enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
struct sk_buff *reasm;
@@ -318,17 +321,18 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key,
if (!reasm)
return -EINPROGRESS;
- if (skb == reasm)
+ if (skb == reasm) {
+ kfree_skb(skb);
return -EINVAL;
+ }
key->ip.proto = ipv6_hdr(reasm)->nexthdr;
skb_morph(skb, reasm);
consume_skb(reasm);
ovs_cb.mru = IP6CB(skb)->frag_max_size;
-#else
- return -EPFNOSUPPORT;
#endif
} else {
+ kfree_skb(skb);
return -EPFNOSUPPORT;
}
@@ -473,6 +477,9 @@ static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
return false;
}
+/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
+ * value if 'skb' is freed.
+ */
int ovs_ct_execute(struct net *net, struct sk_buff *skb,
struct sw_flow_key *key,
const struct ovs_conntrack_info *info)
@@ -508,6 +515,8 @@ int ovs_ct_execute(struct net *net, struct sk_buff *skb,
&info->labels.mask);
err:
skb_push(skb, nh_ofs);
+ if (err)
+ kfree_skb(skb);
return err;
}
diff --git a/net/openvswitch/conntrack.h b/net/openvswitch/conntrack.h
index 82e0dfc66028..a7544f405c16 100644
--- a/net/openvswitch/conntrack.h
+++ b/net/openvswitch/conntrack.h
@@ -67,6 +67,7 @@ static inline int ovs_ct_execute(struct net *net, struct sk_buff *skb,
struct sw_flow_key *key,
const struct ovs_conntrack_info *info)
{
+ kfree_skb(skb);
return -ENOTSUPP;
}