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 304F345C701; Thu, 24 Sep 2026 16:07:16 +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=1790266037; cv=none; b=l/LzyQBwerWNkjipwssUr714mF+UIQVNBFshJTr7KsL/dE8vpv7Um/wZuHUr6WdAo5R56MtVHqykKDLrhCulgZs/jxPUyfraDNs0NByRDcwL1ApNhWOBfo8fxNsYcFmMEWdU/RzWKiobCZti8sH4B3MtnB18nByTxmpj1qzwkuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790266037; c=relaxed/simple; bh=2WsYwVcHFCjHY2sb0hGXPnMy+CyyfC8wOAqnXNtGhxg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=l1fA/8OiqlkKexJz1aqGylIt545bplA1FE5+I/IX57LSTL5n+QvoQKzvvZoBihxjR+9kpAadC6Ho9VQbmcH3trMxCHB+O1dM6FrwnHzQ7mTPAZsVOSFJj7VXD3nPLwDGfYumsmS8qfhVJIA7sFnG2CS5W+qDAKeDYX3Emc48AjY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ijLSFv7y; 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="ijLSFv7y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D46211F00893; Thu, 24 Sep 2026 16:07:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790266036; bh=P/LQL8vJBd6lxTx4gltrEGEIbrleWxLuxoVbeStT2Wo=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ijLSFv7yLVXYWVIhKtsHeCuLQ1uUsdvaVvdZtNtSUG+69sfjKXN3arkIa+Rf6TF99 Jt7uG7PClejRsn3DJdki+koBcIx3EpNJ2g02Wu+lVbOko20wnFkxHE0lgDRJfC57dD bee1PL1HxzjyOCgu5OBunU8mwHVx0E5k+FTXRIgLmFqwYzUwx4kGKIlW1NvAFdb+W2 CLociAO9jeNAIfToGgdnxXtXmU8zAnSr+jridjN4fBbeGZF3XCOtG1SbBBm8qLrlWU GClnp+XhO9XyVLq6jqSMUBTHEmwpkwsGbCugoJjTKaXaljj9D5Qdfax1vm0Rd75hvP iAugqB+EFSLfA== Date: Thu, 24 Sep 2026 09:07:15 -0700 From: Jakub Kicinski To: Hui Peng Cc: Andrew Lunn , "David S . Miller" , Eric Dumazet , Paolo Abeni , Kory Maincent , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ethtool: tsinfo: release net_device reference in ethnl_tsinfo_start() Message-ID: <20260924090715.029f1550@kernel.org> In-Reply-To: <20260919204803.2811673-1-benquike@gmail.com> References: <20260919204803.2811673-1-benquike@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 19 Sep 2026 20:48:03 +0000 Hui Peng wrote: > - if (ctx->req_info->base.dev) { > - struct net_device *dev = ctx->req_info->base.dev; > + if (ctx->single_dev) { > + struct net_device *dev = dev_get_by_index(net, ctx->pos_ifindex); > > + if (!dev) > + return -ENODEV; > netdev_lock_ops_compat(dev); > ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); > netdev_unlock_ops_compat(dev); > + dev_put(dev); > return ret; This issue gotta be theoretical, can you build a repro that actually triggers multi-skb dump for a single netdev? We don't have that much info, it's gonna fit. If you can trigger pls update the commit msg, if you can't let's instead make this "official" by adding: diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c index c9b680a9cc3f..cbb5d6b7f3e3 100644 --- a/net/ethtool/tsinfo.c +++ b/net/ethtool/tsinfo.c @@ -482,6 +482,7 @@ int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb) netdev_lock_ops_compat(dev); ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); netdev_unlock_ops_compat(dev); + /* We don't want to hold the device ref across messages */ + WARN_ON_ONCE(ret == -EMSGSIZE); return ret; }