From patchwork Wed Nov 2 03:54:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wangyufen X-Patchwork-Id: 13027707 X-Patchwork-Delegate: kuba@kernel.org 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 96C6BC4332F for ; Wed, 2 Nov 2022 03:34:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231286AbiKBDeJ (ORCPT ); Tue, 1 Nov 2022 23:34:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231279AbiKBDeF (ORCPT ); Tue, 1 Nov 2022 23:34:05 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31257C9; Tue, 1 Nov 2022 20:34:04 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4N2CD64qbpz15MK2; Wed, 2 Nov 2022 11:33:58 +0800 (CST) Received: from localhost.localdomain (10.175.112.70) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 2 Nov 2022 11:34:01 +0800 From: Wang Yufen To: , CC: , , , , , Wang Yufen Subject: [PATCH net] net: Fix memory leaks of napi->rx_list Date: Wed, 2 Nov 2022 11:54:34 +0800 Message-ID: <1667361274-2621-1-git-send-email-wangyufen@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.70] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org kmemleak reports after running test_progs: unreferenced object 0xffff8881b1672dc0 (size 232): comm "test_progs", pid 394388, jiffies 4354712116 (age 841.975s) hex dump (first 32 bytes): e0 84 d7 a8 81 88 ff ff 80 2c 67 b1 81 88 ff ff .........,g..... 00 40 c5 9b 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace: [<00000000c8f01748>] napi_skb_cache_get+0xd4/0x150 [<0000000041c7fc09>] __napi_build_skb+0x15/0x50 [<00000000431c7079>] __napi_alloc_skb+0x26e/0x540 [<000000003ecfa30e>] napi_get_frags+0x59/0x140 [<0000000099b2199e>] tun_get_user+0x183d/0x3bb0 [tun] [<000000008a5adef0>] tun_chr_write_iter+0xc0/0x1b1 [tun] [<0000000049993ff4>] do_iter_readv_writev+0x19f/0x320 [<000000008f338ea2>] do_iter_write+0x135/0x630 [<000000008a3377a4>] vfs_writev+0x12e/0x440 [<00000000a6b5639a>] do_writev+0x104/0x280 [<00000000ccf065d8>] do_syscall_64+0x3b/0x90 [<00000000d776e329>] entry_SYSCALL_64_after_hwframe+0x63/0xcd The issue occurs in the following scenarios: tun_get_user() napi_gro_frags() napi_frags_finish() case GRO_NORMAL: gro_normal_one() list_add_tail(&skb->list, &napi->rx_list); <-- While napi->rx_count < READ_ONCE(gro_normal_batch), <-- gro_normal_list() is not called, napi->rx_list is not empty ... netif_napi_del() __netif_napi_del() <-- &napi->rx_list is not empty, which caused memory leaks To fix, add flush_rx_list() to free skbs in napi->rx_list. Fixes: 323ebb61e32b ("net: use listified RX for handling GRO_NORMAL skbs") Signed-off-by: Wang Yufen --- net/core/dev.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 3be2560..de3bc9c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6461,6 +6461,16 @@ static void flush_gro_hash(struct napi_struct *napi) } } +static void flush_rx_list(struct napi_struct *napi) +{ + struct sk_buff *skb, *next; + + list_for_each_entry_safe(skb, next, &napi->rx_list, list) { + skb_list_del_init(skb); + kfree_skb(skb); + } +} + /* Must be called in process context */ void __netif_napi_del(struct napi_struct *napi) { @@ -6471,6 +6481,7 @@ void __netif_napi_del(struct napi_struct *napi) list_del_rcu(&napi->dev_list); napi_free_frags(napi); + flush_rx_list(napi); flush_gro_hash(napi); napi->gro_bitmask = 0;