From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF585C433F5 for ; Sun, 20 Feb 2022 11:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235101AbiBTLTW (ORCPT ); Sun, 20 Feb 2022 06:19:22 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:34640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229480AbiBTLTW (ORCPT ); Sun, 20 Feb 2022 06:19:22 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0243145AF5 for ; Sun, 20 Feb 2022 03:19:00 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1nLkF0-0002Z4-B7; Sun, 20 Feb 2022 12:18:58 +0100 From: Florian Westphal To: Cc: Florian Westphal , Fernando Fernandez Mancera Subject: [PATCH v2 nf] netfilter: nf_tables: fix memory leak during stateful obj update Date: Sun, 20 Feb 2022 12:18:50 +0100 Message-Id: <20220220111850.87378-1-fw@strlen.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org stateful objects can be updated from the control plane. The transaction logic allocates a temporary object for this purpose. This object has to be released via nft_obj_destroy, not kfree, since the ->init function was called and it can have side effects beyond memory allocation. Unlike normal NEWOBJ path, the objects module refcount isn't incremented, so add nft_newobj_destroy and use that. Fixes: d62d0ba97b58 ("netfilter: nf_tables: Introduce stateful object update operation") Cc: Fernando Fernandez Mancera Signed-off-by: Florian Westphal --- v2: can't use nft_obj_destroy, module refcount is not incremented. net/netfilter/nf_tables_api.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 5fa16990da95..56208e778982 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6909,6 +6909,15 @@ static int nf_tables_getobj(struct sk_buff *skb, const struct nfnl_info *info, return err; } +/* nf_tables_updobj does not increment module refcount */ +static void nft_newobj_destroy(const struct nft_ctx *ctx, struct nft_object *obj) +{ + if (obj->ops->destroy) + obj->ops->destroy(ctx, obj); + + kfree(obj); +} + static void nft_obj_destroy(const struct nft_ctx *ctx, struct nft_object *obj) { if (obj->ops->destroy) @@ -8185,7 +8194,7 @@ static void nft_obj_commit_update(struct nft_trans *trans) if (obj->ops->update) obj->ops->update(obj, newobj); - kfree(newobj); + nft_newobj_destroy(&trans->ctx, newobj); } static void nft_commit_release(struct nft_trans *trans) @@ -8976,7 +8985,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) break; case NFT_MSG_NEWOBJ: if (nft_trans_obj_update(trans)) { - kfree(nft_trans_obj_newobj(trans)); + nft_newobj_destroy(&trans->ctx, nft_trans_obj_newobj(trans)); nft_trans_destroy(trans); } else { trans->ctx.table->use--; -- 2.35.1