From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753504Ab0HPKzj (ORCPT ); Mon, 16 Aug 2010 06:55:39 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:48641 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751802Ab0HPKzi (ORCPT ); Mon, 16 Aug 2010 06:55:38 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mail-followup-to:mime-version :content-type:content-disposition:user-agent; b=iI5MHqHTdnJD4AHScXnK600c3ZruuN/inLHe3KyaXtjOj9p+D5MGsPA5LXRA8oZ0nf xudrvQU6z9Ay40yFHUnaEpU8b+F/g8kXnG/rYt9SqKYhs4TF1Za5433fQwKPyVFM1lLb hAKDdoZG/sx9OS9QbTmslGEiEgFY4+K/sUVL0= Date: Mon, 16 Aug 2010 12:55:02 +0200 From: Dan Carpenter To: Thomas Gleixner Cc: Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Cliff Wickman , Jack Steiner , Robin Holt , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [patch] tlb_uv: handle large snprintf() returns Message-ID: <20100816105502.GC645@bicker> Mail-Followup-To: Dan Carpenter , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Cliff Wickman , Jack Steiner , Robin Holt , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org snprintf() returns the number of bytes that *would* have been copied if the buffer was large enough, so it can be larger than the size of the buffer. In this case it's ok, but let's put a cap on it anyway so it's easier to audit. Signed-off-by: Dan Carpenter diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c index 312ef02..5e88b3a 100644 --- a/arch/x86/kernel/tlb_uv.c +++ b/arch/x86/kernel/tlb_uv.c @@ -1012,6 +1012,9 @@ static ssize_t tunables_read(struct file *file, char __user *userbuf, timeoutsb4reset, ipi_reset_limit, complete_threshold, congested_response_us, congested_reps, congested_period); + if (ret > 300) + ret = 300; + return simple_read_from_buffer(userbuf, count, ppos, buf, ret); }