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 8FFBCC43217 for ; Wed, 23 Nov 2022 09:14:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237254AbiKWJOi (ORCPT ); Wed, 23 Nov 2022 04:14:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237281AbiKWJOY (ORCPT ); Wed, 23 Nov 2022 04:14:24 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5134D106111 for ; Wed, 23 Nov 2022 01:14:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E30D861B10 for ; Wed, 23 Nov 2022 09:14:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF491C433C1; Wed, 23 Nov 2022 09:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669194856; bh=9T1Ecdju3OV995/kOEJ34eC2q8xjcDQVVhhfNwX0MQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=njCBshvYtU492pOPwo+tSPuJ/WWBr20nxQlDrOMAfKgIBjLFNqvh8NJVsxgEM9nxu EcKu27utJMKtaJ92NwnDovc8FUTOc1HFMpjmorrCylYKRySv8SSa+2JtjD2U6l76Eh oDwHg5y1VGUnwwVbAsH/EBODrQ3Fyltm2Pwq0x44= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Eric Dumazet , Wang Yufen , Jakub Kicinski Subject: [PATCH 5.4 062/156] net: tun: call napi_schedule_prep() to ensure we own a napi Date: Wed, 23 Nov 2022 09:50:19 +0100 Message-Id: <20221123084600.195122112@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084557.816085212@linuxfoundation.org> References: <20221123084557.816085212@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet commit 07d120aa33cc9d9115753d159f64d20c94458781 upstream. A recent patch exposed another issue in napi_get_frags() caught by syzbot [1] Before feeding packets to GRO, and calling napi_complete() we must first grab NAPI_STATE_SCHED. [1] WARNING: CPU: 0 PID: 3612 at net/core/dev.c:6076 napi_complete_done+0x45b/0x880 net/core/dev.c:6076 Modules linked in: CPU: 0 PID: 3612 Comm: syz-executor408 Not tainted 6.1.0-rc3-syzkaller-00175-g1118b2049d77 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:napi_complete_done+0x45b/0x880 net/core/dev.c:6076 Code: c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 24 04 00 00 41 89 5d 1c e9 73 fc ff ff e8 b5 53 22 fa <0f> 0b e9 82 fe ff ff e8 a9 53 22 fa 48 8b 5c 24 08 31 ff 48 89 de RSP: 0018:ffffc90003c4f920 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000030 RCX: 0000000000000000 RDX: ffff8880251c0000 RSI: ffffffff875a58db RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888072d02628 R13: ffff888072d02618 R14: ffff888072d02634 R15: 0000000000000000 FS: 0000555555f13300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c44d3892b8 CR3: 00000000172d2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: napi_complete include/linux/netdevice.h:510 [inline] tun_get_user+0x206d/0x3a60 drivers/net/tun.c:1980 tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2027 call_write_iter include/linux/fs.h:2191 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_writev+0x1aa/0x630 fs/read_write.c:934 do_writev+0x133/0x2f0 fs/read_write.c:977 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f37021a3c19 Fixes: 1118b2049d77 ("net: tun: Fix memory leaks of napi_get_frags") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Wang Yufen Link: https://lore.kernel.org/r/20221107180011.188437-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2002,18 +2002,25 @@ drop: skb_headlen(skb)); if (unlikely(headlen > skb_headlen(skb))) { + WARN_ON_ONCE(1); + err = -ENOMEM; this_cpu_inc(tun->pcpu_stats->rx_dropped); +napi_busy: napi_free_frags(&tfile->napi); rcu_read_unlock(); mutex_unlock(&tfile->napi_mutex); - WARN_ON(1); - return -ENOMEM; + return err; } - local_bh_disable(); - napi_gro_frags(&tfile->napi); - napi_complete(&tfile->napi); - local_bh_enable(); + if (likely(napi_schedule_prep(&tfile->napi))) { + local_bh_disable(); + napi_gro_frags(&tfile->napi); + napi_complete(&tfile->napi); + local_bh_enable(); + } else { + err = -EBUSY; + goto napi_busy; + } mutex_unlock(&tfile->napi_mutex); } else if (tfile->napi_enabled) { struct sk_buff_head *queue = &tfile->sk.sk_write_queue;