From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A53B84CA29C for ; Tue, 9 Jun 2026 19:08:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781032092; cv=none; b=jcygVxuJE2G7IemxxbBWInUIjv2CTKaAi+FKIFDDlsh951tL9ASdM0/pPPhJzSNU5hFMUIDCVRiI/qD5FmIlQBa8feE3d/jChXEnXmFXBarGPNztwAzLQTzXU8w7fEbUrffHGJn+AURjGe4Z5Jt5y32fLKaqsoeikcgV3JWc4nE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781032092; c=relaxed/simple; bh=nlwtcxXtdlWDBQvHdYCXl5s0p6C3lur+YjX93OBYcm8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q835pO1pHgi4oYgPq25+sjGZ2IOVeiy/MWHrX2VLM7a0LWPrTK7KDU7ZBU7WqbQm9XfaJwbFsz6d5xP+rLn2ldT9cPrCxUmhtcYAnQsSD5UCXcmjFgmZiQSI3WpczeeMqED4UH7fASCXujbWZdinVo5Y1aBCl6fQHm1LnJOQVhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kWkL45w/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kWkL45w/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E14A51F00893; Tue, 9 Jun 2026 19:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781032091; bh=GVxi1mVoUgaSl/yFAFc3UoriW9Jty4zjW3nu+EeuZAc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kWkL45w/LS+d4cCnm93KwM3U4rc4Eemm9laE+ZkAcbKlJdz0MQ/wKy/Gqs/KP/ol/ 8Dh/ceL7nM7cc7+lfmA41NdBLsi3QeZdJfP8jgMxoFXPr1tJaRckqLCSDMQ3ahm6eY 1B28eGoaTKlp1o9cS24aIoEJkgML/MKo5jFqqVT/X+M9td44nAwqwd7oWBUTHkAY2M jtV6AHBTi/KTWmzrJhtQyLZgmt5ZNK0+4xX/J8wRf7WxOXZA5rA7M94rOYoCj5zsH/ rpTcvILLj4vpeio+NYYgU/3JTnTq7Y4h4sMtHCkY3eB5UwLBtzHbXuJuOJfzya8T2M JXbX5FGvx7CXg== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, dw@davidwei.uk, daniel@iogearbox.net, razor@blackwall.org, sdf@fomichev.me, dtatulea@nvidia.com, bobbyeshleman@meta.com, Jakub Kicinski Subject: [PATCH net-next 3/4] netdev: avoid skipping objects on race with device disappearance Date: Tue, 9 Jun 2026 12:08:03 -0700 Message-ID: <20260609190804.1137085-4-kuba@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260609190804.1137085-1-kuba@kernel.org> References: <20260609190804.1137085-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If the currently dumped device disappears while we were mid-dump we will get the next device without resetting the sub-object ID. This is quite unlikely, it was reported by an AI tool not a real user. Let's fix it for better dump consistency. Signed-off-by: Jakub Kicinski --- net/core/netdev-genl.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index d35af460e886..18046ad0f883 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -310,11 +310,14 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) err = -ENODEV; } } else { + unsigned long start_ifindex = ctx->ifindex; + for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) { + if (ctx->ifindex != start_ifindex) + ctx->napi_id = 0; err = netdev_nl_napi_dump_one(netdev, skb, info, ctx); if (err < 0) break; - ctx->napi_id = 0; } } @@ -634,13 +637,17 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) err = -ENODEV; } } else { + unsigned long start_ifindex = ctx->ifindex; + for_each_netdev_lock_ops_compat_scoped(net, netdev, ctx->ifindex) { + if (ctx->ifindex != start_ifindex) { + ctx->rxq_idx = 0; + ctx->txq_idx = 0; + } err = netdev_nl_queue_dump_one(netdev, skb, info, ctx); if (err < 0) break; - ctx->rxq_idx = 0; - ctx->txq_idx = 0; } } @@ -786,8 +793,6 @@ netdev_nl_stats_by_queue(struct net_device *netdev, struct sk_buff *rsp, ctx->txq_idx = ++i; } - ctx->rxq_idx = 0; - ctx->txq_idx = 0; return 0; } @@ -902,6 +907,7 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb, struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb); const struct genl_info *info = genl_info_dump(cb); struct net *net = sock_net(skb->sk); + unsigned long start_ifindex; struct net_device *netdev; unsigned int ifindex; unsigned int scope; @@ -934,7 +940,13 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb, return err; } + start_ifindex = ctx->ifindex; + for_each_netdev_lock_ops_compat_scoped(net, netdev, ctx->ifindex) { + if (ctx->ifindex != start_ifindex) { + ctx->rxq_idx = 0; + ctx->txq_idx = 0; + } err = netdev_nl_qstats_get_dump_one(netdev, scope, skb, info, ctx); if (err < 0) -- 2.54.0