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>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/core/flow.c b/net/core/flow.c
index bf32c33cad3b..47b6d26c2afb 100644
--- 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));