From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> In-Reply-To: <20181016170515.447235311@linuxfoundation.org> References: <20181016170515.447235311@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 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;