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="R/SGTLgL" Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8980E6 for ; Fri, 17 Nov 2023 22:58:14 -0800 (PST) Received: by mail-pf1-x42f.google.com with SMTP id d2e1a72fcca58-6b5cac99cfdso2538167b3a.2 for ; Fri, 17 Nov 2023 22:58:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700290694; x=1700895494; 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=S4So+f19Iw9wK9Z0NOg4xqdd1JDG75Z0QdBaz25kwqg=; b=R/SGTLgLub+5U1NrXdh5djKewA2YSfPLgUzfAJkqgFAekLp/wpn423+OPGZa2Oqjb0 dZwGFM64uJ+ur2dC2ycMkTFoZ5Wkpo6xWa5+yRiGIfAIuSSwL5iY2LK42DXdw5pNazw8 fg+ZPhrYv2EzCpIT4zmCFhFzoyxthUkGzJJkrqRFUyP9a8OsUdih9v4Tzewa8o+GzTKQ 9k2LXwwYL7HVsYiYotMSbZ1sI8bOuBI9zdb9xybmpIAY5C45soM9XBdOATb54ypLeAfi 9v6Pr0404UP2b6vphS++upb34jZgRwkPkRtxGvrUkyVqF1dYHCAoWFKkXO7EU6+PVaI3 nVlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700290694; x=1700895494; 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=S4So+f19Iw9wK9Z0NOg4xqdd1JDG75Z0QdBaz25kwqg=; b=cNRwMJlpcGaHDgnIp85Pqsei6YQnGq+UbBJ7xMbz++ahiASg/scuNCajibbw4SodWW h28cCOyjx1iZaT5LVWn773RkwHkv0hbFVXsJ4GU10qmMPL1dfCswoAiFyBUp7330sGk/ HC9BWikEizq0y6TSgBO7uUE5rjOyrb9dVNK0sDoKVh3LLK6zmvldVPcpyHY9fU3ay5zl /axuGaZrjvPVHPwOINSA3v1cTT6TdxyXwp8Nz7gv1+hvr5sOl5teLzLux4MWK3YksvVP Vk7yw/9QcPIUopVXodxTGJQ4hamiIUngASvt6J2C4rOaeD4N+E7CPB3XF1JR+2SAB3sk TaIw== X-Gm-Message-State: AOJu0Yz9vU8V0wKSqpFei7hRtgdbiLpCsWyJ6njDzORp02g00Pq6IbGs XLMK2kuXB4xSrcnlrFN4iBY= X-Google-Smtp-Source: AGHT+IEj1kGsLQ9DOvAx+VA4nwX1ijmHK0/Z9ZOECzWQyxZdyk2ihYBTkuW4vgk/Sif9RlKyFEYrLQ== X-Received: by 2002:a17:902:904a:b0:1cc:1ee2:d41d with SMTP id w10-20020a170902904a00b001cc1ee2d41dmr1461936plz.39.1700290694167; Fri, 17 Nov 2023 22:58:14 -0800 (PST) Received: from Laptop-X1 ([43.228.180.230]) by smtp.gmail.com with ESMTPSA id a2-20020a170902900200b001cc3c521affsm2364045plp.300.2023.11.17.22.58.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Nov 2023 22:58:13 -0800 (PST) Date: Sat, 18 Nov 2023 14:58:03 +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 v2 net] wireguard: use DEV_STATS_INC() Message-ID: References: <20231117141733.3344158-1-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: <20231117141733.3344158-1-edumazet@google.com> On Fri, Nov 17, 2023 at 02:17:33PM +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 > ... > > v2: also change wg_packet_consume_data_done() (Hangbin Liu) > and wg_packet_purge_staged_packets() > > Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") > Reported-by: syzbot > Signed-off-by: Eric Dumazet > Cc: Jason A. Donenfeld > Cc: Hangbin Liu > --- I respect Jason's comments. Reviewed-by: Hangbin Liu