[PATCH nf] netfilter: nf_flow_table: fix missing err check for rhashtable_insert_fast

[Taehee Yoo]

rhashtable_insert_fast() could return err value when memory allocation
is failed. but flow_offload_add() do not check values and this always
returns success value.
This patch just adds error check code.

Fixes: ac2a66665e23 ("netfilter: add generic flow table infrastructure")
Signed-off-by: Taehee Yoo <ap420...@gmail.com>
---
 net/netfilter/nf_flow_table_core.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nf_flow_table_core.c 
b/net/netfilter/nf_flow_table_core.c
index 7aabfd4b1e50..a9e4f74b1ff6 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -185,14 +185,25 @@ static const struct rhashtable_params 
nf_flow_offload_rhash_params = {
 
 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload 
*flow)
 {
-       flow->timeout = (u32)jiffies;
+       int err;
 
-       rhashtable_insert_fast(&flow_table->rhashtable,
-                              &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
-                              nf_flow_offload_rhash_params);
-       rhashtable_insert_fast(&flow_table->rhashtable,
-                              &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
-                              nf_flow_offload_rhash_params);
+       err = rhashtable_insert_fast(&flow_table->rhashtable,
+                                    &flow->tuplehash[0].node,
+                                    nf_flow_offload_rhash_params);
+       if (err < 0)
+               return err;
+
+       err = rhashtable_insert_fast(&flow_table->rhashtable,
+                                    &flow->tuplehash[1].node,
+                                    nf_flow_offload_rhash_params);
+       if (err < 0) {
+               rhashtable_remove_fast(&flow_table->rhashtable,
+                                      &flow->tuplehash[0].node,
+                                      nf_flow_offload_rhash_params);
+               return err;
+       }
+
+       flow->timeout = (u32)jiffies;
        return 0;
 }
 EXPORT_SYMBOL_GPL(flow_offload_add);
-- 
2.17.1