net: Make flow cache namespace-aware

flow_cache_lookup will return a cached object (or null pointer) that the
resolver (i.e. xfrm_policy_lookup) previously found for another namespace
using the same key/family/dir.  Instead, make the namespace part of what
identifies entries in the cache.

As before, flow_entry_valid will return 0 for entries where the namespace
has been deleted, and they will be removed from the cache the next time
flow_cache_gc_task is run.

Reported-by: Andrew Dickinson <whydna@whydna.net>
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/flow.c b/net/core/flow.c
index bf32c33..47b6d26 100644 (file)
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -30,6 +30,7 @@ struct flow_cache_entry {
                struct hlist_node       hlist;
                struct list_head        gc_list;
        } u;
+       struct net                      *net;
        u16                             family;
        u8                              dir;
        u32                             genid;
@@ -232,7 +233,8 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 
        hash = flow_hash_code(fc, fcp, key);
        hlist_for_each_entry(tfle, entry, &fcp->hash_table[hash], u.hlist) {
-               if (tfle->family == family &&
+               if (tfle->net == net &&
+                   tfle->family == family &&
                    tfle->dir == dir &&
                    flow_key_compare(key, &tfle->key) == 0) {
                        fle = tfle;
@@ -246,6 +248,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 
                fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
                if (fle) {
+                       fle->net = net;
                        fle->family = family;
                        fle->dir = dir;
                        memcpy(&fle->key, key, sizeof(*key));