From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CJH7Ixmt" Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65CC1129 for ; Thu, 16 Nov 2023 17:34:53 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id 41be03b00d2f7-5be24d41bb8so1101000a12.0 for ; Thu, 16 Nov 2023 17:34:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700184893; x=1700789693; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Fu1MfOOQ0QmPKbRiBlMZVcOZDRZgiPGzQljwLltlcro=; b=CJH7IxmtX89GcaEiTzQ80DFsQdmsxEic2aG//+l0vVpIXgnr01BK6jyD3PLJs+3oJc oGNXB9AefPn/V8oxm+RgKXrsHs211tJxOw2Thi2fxtEq5+0AMPR9MjUsFphNb8rit8mW ddiUbg5UVUoypYg2/7strydfr7+hfkEXrnTi01ZDK9oKQYHPPpeWA8Ls0fqSTxdxrwVu 4iSvzzwo9WkbU4RTTdT19hihtWGxC5VJEWuCIgaX/KEKNl3+5FAxujK4dgidHnpuL4Y1 Dw478wozOMNFZ7TLkfu3Q0m9BJd8+Jkl83ldrvDf8wWBcG0TWbsEs91VoKDAn7DcBXVQ byoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700184893; x=1700789693; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Fu1MfOOQ0QmPKbRiBlMZVcOZDRZgiPGzQljwLltlcro=; b=bwmRxgZPsJG//wZrxdm1y6VtUoD0cuDN1MxQm0Yalw4jLad4kFH5xuK7rVwgPgnDDB uhllFQFed1ynjRf8sFeDJt+uzlDD9npCbgA1leWnjXPDra2XWQG2Q5BTmpghj1JixRKA lBgyJ5T68W8cMncTB+L/7YAJtUYrSR+eW66fvKLhBOjdNz9lOkubpAfF/kbDuHD6fJUZ LCMoQLuc1dqf1OPkvTmaU1/20YGjsmNnoAcGTGl13jJGWQjTd3wnK6dG+a3LzktYl72V uRtC7cpKJ0Kdfla0d5iHe1k8VLBzJyX1Wbh4I6wo9DZGE4rdgAqQEWwemTWJ8LQ+odC/ FvcA== X-Gm-Message-State: AOJu0YwLRmfhdn2fxAI+ApYixUiaB+CrTb4GV6sos+/wTjbHZnVaUnLd NoIx/cUptFkXFzsspx+cikw= X-Google-Smtp-Source: AGHT+IHQ9Mbxhp0ZeczUcI2QnSjpX4PvuU8sTlg6D0+XbSrA3YxaL5sbwWEkU5UabSxar9SvkzTtow== X-Received: by 2002:a17:90b:44:b0:280:6cde:ecc2 with SMTP id d4-20020a17090b004400b002806cdeecc2mr4908850pjt.11.1700184892729; Thu, 16 Nov 2023 17:34:52 -0800 (PST) Received: from Laptop-X1 ([43.228.180.230]) by smtp.gmail.com with ESMTPSA id x10-20020a17090aa38a00b0028328057c67sm293796pjp.45.2023.11.16.17.34.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Nov 2023 17:34:52 -0800 (PST) Date: Fri, 17 Nov 2023 09:34:47 +0800 From: Hangbin Liu To: Eric Dumazet Cc: "David S . Miller" , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, eric.dumazet@gmail.com, syzbot , "Jason A . Donenfeld" Subject: Re: [PATCH net] wireguard: use DEV_STATS_INC() Message-ID: References: <20231116100217.2654521-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231116100217.2654521-1-edumazet@google.com> On Thu, Nov 16, 2023 at 10:02:17AM +0000, Eric Dumazet wrote: > wg_xmit() can be called concurrently, KCSAN reported [1] > some device stats updates can be lost. > > Use DEV_STATS_INC() for this unlikely case. > > [1] > BUG: KCSAN: data-race in wg_xmit / wg_xmit > > read-write to 0xffff888104239160 of 8 bytes by task 1375 on cpu 0: > wg_xmit+0x60f/0x680 drivers/net/wireguard/device.c:231 > __netdev_start_xmit include/linux/netdevice.h:4918 [inline] > netdev_start_xmit include/linux/netdevice.h:4932 [inline] > xmit_one net/core/dev.c:3543 [inline] > dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3559 > ... > > read-write to 0xffff888104239160 of 8 bytes by task 1378 on cpu 1: > wg_xmit+0x60f/0x680 drivers/net/wireguard/device.c:231 > __netdev_start_xmit include/linux/netdevice.h:4918 [inline] > netdev_start_xmit include/linux/netdevice.h:4932 [inline] > xmit_one net/core/dev.c:3543 [inline] > dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3559 > ... > > Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") > Reported-by: syzbot > Signed-off-by: Eric Dumazet > Cc: Jason A. Donenfeld > --- > drivers/net/wireguard/device.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c > index 258dcc1039216f311a223fd348295d4b5e03a3ed..deb9636b0ecf8f47e832a0b07e9e049ba19bdf16 100644 > --- a/drivers/net/wireguard/device.c > +++ b/drivers/net/wireguard/device.c > @@ -210,7 +210,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) > */ > while (skb_queue_len(&peer->staged_packet_queue) > MAX_STAGED_PACKETS) { > dev_kfree_skb(__skb_dequeue(&peer->staged_packet_queue)); > - ++dev->stats.tx_dropped; > + DEV_STATS_INC(dev, tx_dropped); > } > skb_queue_splice_tail(&packets, &peer->staged_packet_queue); > spin_unlock_bh(&peer->staged_packet_queue.lock); > @@ -228,7 +228,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) > else if (skb->protocol == htons(ETH_P_IPV6)) > icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); > err: > - ++dev->stats.tx_errors; > + DEV_STATS_INC(dev, tx_errors); > kfree_skb(skb); > return ret; > } > -- > 2.43.0.rc0.421.g78406f8d94-goog > Reviewed-by: Hangbin Liu BTW, what about the receive part function wg_packet_consume_data_done(), do we need to use DEV_STATS_INC()? Thanks Hangbin