From patchwork Thu Apr 11 11:28:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13625767 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F0F8613BACD; Thu, 11 Apr 2024 11:29:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.188.207 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712834953; cv=none; b=I7vmHYWbzZ5ZcWccDAlb3RyZLV1phIhDHW2nJP04CwIrB94ueBEszEkyQGC44Hfw5vl14auhi/XarFfLzQRv8PED3J+FqGOcNsm/xlDF67VHXav0sDpfxUposrNXiKKwS5oBZDSR/1yoEoeCg7ExvLVBrcfUbYQ2fQuAgE2O0mA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712834953; c=relaxed/simple; bh=i9VkAHjxVSR2v7wAIqFrQ8rTNs3tdMKBAJwrdz/74Xg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cxbn0FVs+J4h+IcN696FvSalHhFNtcezULKXvb7Fg4loyIcxljjJI91fiHt/u89p2xTManT8i2pnUU7XkdoSdPNTiBTZFwFsSPrjr4wosszifcIlNc57ZY0UuQbkQ9WXFYfqWXbEuNLtUrc6hw9/WCK1f/bbjV9SnxP6glnFPNI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; arc=none smtp.client-ip=217.70.188.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de Subject: [PATCH net 2/7] netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get() Date: Thu, 11 Apr 2024 13:28:55 +0200 Message-Id: <20240411112900.129414-3-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240411112900.129414-1-pablo@netfilter.org> References: <20240411112900.129414-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Ziyang Xuan nft_unregister_obj() can concurrent with __nft_obj_type_get(), and there is not any protection when iterate over nf_tables_objects list in __nft_obj_type_get(). Therefore, there is potential data-race of nf_tables_objects list entry. Use list_for_each_entry_rcu() to iterate over nf_tables_objects list in __nft_obj_type_get(), and use rcu_read_lock() in the caller nft_obj_type_get() to protect the entire type query process. Fixes: e50092404c1b ("netfilter: nf_tables: add stateful objects") Signed-off-by: Ziyang Xuan Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 53b8c00863ad..f11d0c0a2c73 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7611,7 +7611,7 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype, u8 family) { const struct nft_object_type *type; - list_for_each_entry(type, &nf_tables_objects, list) { + list_for_each_entry_rcu(type, &nf_tables_objects, list) { if (type->family != NFPROTO_UNSPEC && type->family != family) continue; @@ -7627,9 +7627,13 @@ nft_obj_type_get(struct net *net, u32 objtype, u8 family) { const struct nft_object_type *type; + rcu_read_lock(); type = __nft_obj_type_get(objtype, family); - if (type != NULL && try_module_get(type->owner)) + if (type != NULL && try_module_get(type->owner)) { + rcu_read_unlock(); return type; + } + rcu_read_unlock(); lockdep_nfnl_nft_mutex_not_held(); #ifdef CONFIG_MODULES