From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B16C284A50 for ; Thu, 21 Mar 2024 14:30:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711031448; cv=none; b=k+H3u+zkDmHYhqTw63dC0ZWudwT7PmUH1KfvNRKa3NnyO9SriB3Af2gVtvEx3GutgnY2WCWv0AcxY0iK8GXb4AnVKCErXbedRyJ9TANf7YEDIYdM0bj5M2V7ep0tUa3tcFZMZpgZLOE0l1sbiJciPTei7yXoWcPV4AqZ5BYMcvM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711031448; c=relaxed/simple; bh=pQtjH+pTMInREJIjM32PY8nkyllfkOtwzCUnNyEAvoM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rDXtVLtaSwPZPKu9zm/s8Bh+MadzXMe+ESi+Bn6L358X/Om/xGeMUjho0esd99Y4gglss2TxlbjhLzjwvhjZRD6ybWdRTTmgMs4UdvmUuboyUmMqNI6F1priv5xf6li8MIjVXipHLS4Q+wBGy0enLu7iRVjLtIXZi9aG2VmGA6o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=InpN5d4J; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="InpN5d4J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C87FCC433C7; Thu, 21 Mar 2024 14:30:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711031448; bh=pQtjH+pTMInREJIjM32PY8nkyllfkOtwzCUnNyEAvoM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=InpN5d4JGUiZDotzf/3UiUg25jT0g1aLzvjeSWkcbHStOkF0syLA4mMJwQ+zz0vbb BiqyZUe73eIbCJ5857ji0WVJjnaNMNDyaiuuIWzDVXL0RIqKANhMglLdOh9ucImZwQ MIJQfa0LvodFBNt9t2bx+wzS1cshoWiU+Yt8geT+9qwjeJntPwmgdLWafwIOZuGGSL oYtDVRMQ9F6dCahnrvTRhh3j1Fdx5AH8SZ71OWJ2DmQOlPAorTw4u8IyvfOdm29FCe 4BC6IEz3/Fg3N+2TTxM7AFPd4nPLd0qJWMLoCzWfznzFliRUhhXr683lfAeSA4JDUy S9YI26LWhrBFw== Date: Thu, 21 Mar 2024 07:30:45 -0700 From: Jakub Kicinski To: renmingshuai Cc: , , , , , , , Subject: Re: [PATCH] net/netlink: how to deal with the problem of exceeding the maximum reach of nlattr's nla_len Message-ID: <20240321073045.3ee6127d@kernel.org> In-Reply-To: <20240321141400.38639-1-renmingshuai@huawei.com> References: <20240321141400.38639-1-renmingshuai@huawei.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-Transfer-Encoding: 7bit On Thu, 21 Mar 2024 22:14:00 +0800 renmingshuai wrote: > RTM_GETLINK for greater than about 220 VFs truncates IFLA_VFINFO_LIST > due to the maximum reach of nlattr's nla_len being exceeded. As a result, > the value of nla_len overflows in nla_nest_end(). According to [1], > changing the type of nla_len is not possible, but how can we deal with this > overflow problem? The nla_len is constantly set to the > maximum value when it overflows? Or some better ways? It's a known limitation of the legacy SRIOV VF API. Use switchdev mode instead, please.