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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6F2AC04EBD for ; Tue, 16 Oct 2018 17:11:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 714072098A for ; Tue, 16 Oct 2018 17:11:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="epy406gz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 714072098A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728206AbeJQBC4 (ORCPT ); Tue, 16 Oct 2018 21:02:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:44598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727246AbeJQBCz (ORCPT ); Tue, 16 Oct 2018 21:02:55 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC9422098A; Tue, 16 Oct 2018 17:11:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539709893; bh=4fov1EAoCm3yRX75UW1GbcExLZzZo72c5U4YX87C/EU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=epy406gz6RVMJozMyPPpIjqvSkdspnP/sXCnAobMIQI51IxQNHGxhR/HDOvXtwP4p fOf3yB9tKL8svw89uwyrAv2WLZk3xZtH/6orZKBzZe2YIszOG37BdWn9s42LYIcTP7 kN462AgDS3ph8f28nbSUStDlnOyppmF+DUY9h9SE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot+e662df0ac1d753b57e80@syzkaller.appspotmail.com, "David S. Miller" Subject: [PATCH 4.18 031/135] tun: initialize napi_mutex unconditionally Date: Tue, 16 Oct 2018 19:04:21 +0200 Message-Id: <20181016170517.200157017@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181016170515.447235311@linuxfoundation.org> References: <20181016170515.447235311@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit c7256f579f8302ce2c038181c30060d0b40017b2 ] This is the first part to fix following syzbot report : console output: https://syzkaller.appspot.com/x/log.txt?x=145378e6400000 kernel config: https://syzkaller.appspot.com/x/.config?x=443816db871edd66 dashboard link: https://syzkaller.appspot.com/bug?extid=e662df0ac1d753b57e80 Following patch is fixing the race condition, but it seems safer to initialize this mutex at tfile creation anyway. Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet Reported-by: syzbot+e662df0ac1d753b57e80@syzkaller.appspotmail.com Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -319,7 +319,6 @@ static void tun_napi_init(struct tun_str netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll, NAPI_POLL_WEIGHT); napi_enable(&tfile->napi); - mutex_init(&tfile->napi_mutex); } } @@ -3241,6 +3240,7 @@ static int tun_chr_open(struct inode *in return -ENOMEM; } + mutex_init(&tfile->napi_mutex); RCU_INIT_POINTER(tfile->tun, NULL); tfile->flags = 0; tfile->ifindex = 0;