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 BC4D3C4332F for ; Wed, 2 Nov 2022 09:22:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229709AbiKBJWe (ORCPT ); Wed, 2 Nov 2022 05:22:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230381AbiKBJV2 (ORCPT ); Wed, 2 Nov 2022 05:21:28 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E03AC11C23; Wed, 2 Nov 2022 02:20:47 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4N2Lvv3M9KzHvV3; Wed, 2 Nov 2022 17:20:27 +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 17:20:45 +0800 From: Wang Yufen To: , CC: , , , , , Wang Yufen Subject: [PATCH net v2] net: tun: Fix memory leaks of napi_get_frags Date: Wed, 2 Nov 2022 17:41:19 +0800 Message-ID: <1667382079-6499-1-git-send-email-wangyufen@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.112.70] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.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 <-- not ask to complete the gro work, will cause memory leaks in <-- following tun_napi_del() ... tun_napi_del() netif_napi_del() __netif_napi_del() <-- &napi->rx_list is not empty, which caused memory leaks To fix, add napi_complete() after napi_gro_frags(). Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Wang Yufen --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 27c6d23..07a0a61 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1976,6 +1976,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, local_bh_disable(); napi_gro_frags(&tfile->napi); + napi_complete(&tfile->napi); local_bh_enable(); mutex_unlock(&tfile->napi_mutex); } else if (tfile->napi_enabled) { -- 1.8.3.1