diff mbox series

[nf,3/4] netfilter: nf_tables: fix memory leaks on chain rename

Message ID 20180717051756.19642-4-fw@strlen.de
State Accepted
Delegated to: Pablo Neira
Headers show
Series netfilter: nf_tables: fix resource leaks | expand

Commit Message

Florian Westphal July 17, 2018, 5:17 a.m. UTC 
The new name is stored in the transaction metadata, on commit,
the pointers to the old and new names are swapped.

Therefore in abort and commit case we have to free the
pointer in the chain_trans container.

In commit case, the pointer can be used by another cpu that
is currently dumping the renamed chain, thus kfree needs to
happen after waiting for rcu readers to complete.

Fixes: b7263e071a ("netfilter: nf_tables: Allow chain name of up to 255 chars")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nf_tables_api.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 8c90cdbb738b..807243f024d7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6083,6 +6083,9 @@  static void nft_commit_release(struct nft_trans *trans)
 	case NFT_MSG_DELTABLE:
 		nf_tables_table_destroy(&trans->ctx);
 		break;
+	case NFT_MSG_NEWCHAIN:
+		kfree(nft_trans_chain_name(trans));
+		break;
 	case NFT_MSG_DELCHAIN:
 		nf_tables_chain_destroy(&trans->ctx);
 		break;
@@ -6312,13 +6315,15 @@  static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 			nf_tables_table_notify(&trans->ctx, NFT_MSG_DELTABLE);
 			break;
 		case NFT_MSG_NEWCHAIN:
-			if (nft_trans_chain_update(trans))
+			if (nft_trans_chain_update(trans)) {
 				nft_chain_commit_update(trans);
-			else
+				nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN);
+				/* trans destroyed after rcu grace period */
+			} else {
 				nft_clear(net, trans->ctx.chain);
-
-			nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN);
-			nft_trans_destroy(trans);
+				nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN);
+				nft_trans_destroy(trans);
+			}
 			break;
 		case NFT_MSG_DELCHAIN:
 			nft_chain_del(trans->ctx.chain);
@@ -6468,7 +6473,7 @@  static int __nf_tables_abort(struct net *net)
 		case NFT_MSG_NEWCHAIN:
 			if (nft_trans_chain_update(trans)) {
 				free_percpu(nft_trans_chain_stats(trans));
-
+				kfree(nft_trans_chain_name(trans));
 				nft_trans_destroy(trans);
 			} else {
 				trans->ctx.table->use--;