From nobody Sun Feb 8 02:56:22 2026 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F6F9397AA0 for ; Wed, 14 Jan 2026 12:26:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768393591; cv=none; b=kzGnNd4MqJVxRXTWpJPZzB7J2vujiDcgy45IZ0+dUjeqW8298kwpMTC8suGDjmmn4PaSm+gK4L4sZSmeKfZnCXMsceyZpxZiFucPUZQHYLNmiMk5sDsJcpCTZfgeRTXBFC8dv3UcRZZ++9m2xFq2OsTTN3DfR2QbhXvtumDngRI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768393591; c=relaxed/simple; bh=JEDnlZYXIHilnOnTePLHzYAZD0ZmBByyDO4WzTOYCCk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dQd3jvI0XgNN8iQ7YMxgaGVbXA3VJxE8QaxkVlsvyehz+wZ+5OYUCS8mqC2Xa1AFMjroLm2MOIVrSjtu+4+ZtlQx3EXOBSeNpumkwz5L78MX9UzU7M+0mJL7/vLB9mclQMTZFWV+QSYuzKgnPNLDnAhdJ9A0SKZ/nrannU9GdTg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=b1i75yib; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="b1i75yib" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-2a0d52768ccso58026095ad.1 for ; Wed, 14 Jan 2026 04:26:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1768393584; x=1768998384; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=AbzNlyftwKRg9xsu0MFnIl7dchtZzqwBBSHtb8zwf2M=; b=b1i75yibxVgOr/Wjjc2QVYZnW3+jOTNz6BFEGAG0QuwV6TL7zfwc22aNfLk3bcD56o NYZ9Gop1frF7BfSHJnfDOf4NwWmYpMqbppapjspV4Zc2fYa0lPtlZJrXfE8W964peLnj mTiomx4X7nHZFwNFMwyz6REat4rCwtlnqhTCRKeD3OXumaxEHD0rMZED3xnu9VzYku2m Z3PpUFVzZ4YNYJZfIlsVdCA4+Y/G4fWGxsVj9EUB2H2OskVHbQGyjH1yatTkPWndV2Q+ ZwvYKgRZQP1B9CUhhzr3PCz7aV9NsjYdW5dyomLar7sp8Bqkip+p890a0DvNf/s8lI03 3jJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768393584; x=1768998384; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=AbzNlyftwKRg9xsu0MFnIl7dchtZzqwBBSHtb8zwf2M=; b=rnwV4zW2s5azOqsglCVsm5uWmeM5CQWV5DUZfiflGWq4RnjF6pfDIx7JTeCayRcwN7 g0qkmRkUQY/0Fmj6ycEYSYugg9eVKEC5omlAxz79+eJT5m09PUIu/U9gC8cAYcbrqLtO jfWJ7AuTT2eiA0U4+hIBcSYZ9VCOhsVgJeYuwSF61f9UKa4A7pRv7wyigbWk5YkkkkM8 pYHHKebOg82rVKIQkfSygk1tkvp2UgHv5EbvaKBpmoTQoxNZ3AUUfrgLm27O+cSEtRpV pgj+6v/j54WSBPYqYy6WMadLwdMvxKd4TL2nyE8w87P7lVch9ZRF/y7RTXjMfJB/Im9m rUuw== X-Forwarded-Encrypted: i=1; AJvYcCU5iOSewd8cokl1KELDCnWFzKb3gUcCgBqa7NCQTytSjyFFd+1wmygG9pyhEIQewHbvSM796nNEyFErIG8=@vger.kernel.org X-Gm-Message-State: AOJu0YyKdsj4G60BFjxqJSpNvBO30CKFigtig+1RvQB/7bD5tEhdEcCz Ez5GOQwWjYHi2g0ZfohY5g4Maca3d4QM+y5Vcoe2W0R0DNtQU+Dgr0l+ X-Gm-Gg: AY/fxX4Ycad9qh+fUwQoghxdMv9q+NAi0mTmNHugIImJPGHrObonKmpHEifvXK6BaGX qCWEs8qZcTHgk3Uu7KxMHqXU9sAUEX3YaY/5U05amKXyG951ydbk0MB0HZOeow6ZBsMGGRCyWjQ DhDEVEXMhXP+KVeXvZK6hXLy3fYECEo20+ysf1HxdB3ooZhk59IavZ3Zir2gmRdHanx0yffuRLH OCSfQwbK00ncoCnwyuAXe9ww5HNpRStx5o7jlFhzRqtCUGEiEXLmaxhP700yeQqir8C4A3BVA8/ W3Jf0g/hZcWQxTh+eOdcBuaijUoB3ALTQBKh1w7ImYHZzVNguRbGS7atshvqsGVDb/vi6nXZGzj PpkVMuFFmBwTKE/agruRlzbda4+TNH/b3Y49c2iM8lI7a/QJa9Hy+5HECxF1v2iGqc0iKEaGRGK fNeMEcSWCPEGbDZpZb7DQ5z727LVHWMxqq/t4+3O/wBU2lIKlZaEJdfQ== X-Received: by 2002:a17:903:40d2:b0:2a0:d34f:aff3 with SMTP id d9443c01a7336-2a59bb36674mr24558905ad.18.1768393584056; Wed, 14 Jan 2026 04:26:24 -0800 (PST) Received: from d.home.mmyangfl.tk ([2001:19f0:8001:1644:5400:5ff:fe3e:12b1]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2a3e3cd4401sm230327115ad.92.2026.01.14.04.25.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jan 2026 04:25:57 -0800 (PST) From: David Yang To: netdev@vger.kernel.org Cc: David Yang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH net-next] veth: fix data race in veth_get_ethtool_stats Date: Wed, 14 Jan 2026 20:24:45 +0800 Message-ID: <20260114122450.227982-1-mmyangfl@gmail.com> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In veth_get_ethtool_stats(), some statistics protected by u64_stats_sync, are read and accumulated in ignorance of possible u64_stats_fetch_retry() events. These statistics, peer_tq_xdp_xmit and peer_tq_xdp_xmit_err, are already accumulated by veth_xdp_xmit(). Fix this by reading them into a temporary buffer first. Signed-off-by: David Yang --- drivers/net/veth.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 14e6f2a2fb77..9982412fd7f2 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -228,16 +228,20 @@ static void veth_get_ethtool_stats(struct net_device = *dev, const struct veth_rq_stats *rq_stats =3D &rcv_priv->rq[i].stats; const void *base =3D (void *)&rq_stats->vs; unsigned int start, tx_idx =3D idx; + u64 buf[VETH_TQ_STATS_LEN]; size_t offset; =20 - tx_idx +=3D (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN; do { start =3D u64_stats_fetch_begin(&rq_stats->syncp); for (j =3D 0; j < VETH_TQ_STATS_LEN; j++) { offset =3D veth_tq_stats_desc[j].offset; - data[tx_idx + j] +=3D *(u64 *)(base + offset); + buf[j] =3D *(u64 *)(base + offset); } } while (u64_stats_fetch_retry(&rq_stats->syncp, start)); + + tx_idx +=3D (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN; + for (j =3D 0; j < VETH_TQ_STATS_LEN; j++) + data[tx_idx + j] +=3D buf[j]; } pp_idx =3D idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN; =20 --=20 2.51.0