From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F697C10F25 for ; Wed, 11 Mar 2020 07:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3AF1208E4 for ; Wed, 11 Mar 2020 07:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728308AbgCKHMH (ORCPT ); Wed, 11 Mar 2020 03:12:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:34092 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbgCKHMH (ORCPT ); Wed, 11 Mar 2020 03:12:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E1225AF4E; Wed, 11 Mar 2020 07:12:05 +0000 (UTC) From: Takashi Iwai To: Greg Kroah-Hartman Cc: "Rafael J . Wysocki" , linux-kernel@vger.kernel.org Subject: [PATCH] drivers/base/cpu: Use scnprintf() for avoiding potential buffer overflow Date: Wed, 11 Mar 2020 08:12:00 +0100 Message-Id: <20200311071200.4024-1-tiwai@suse.de> X-Mailer: git-send-email 2.16.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai --- drivers/base/cpu.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 6265871a4af2..0abcd9d68714 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -231,7 +231,7 @@ static struct cpu_attr cpu_attrs[] = { static ssize_t print_cpus_kernel_max(struct device *dev, struct device_attribute *attr, char *buf) { - int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1); + int n = scnprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1); return n; } static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); @@ -258,13 +258,13 @@ static ssize_t print_cpus_offline(struct device *dev, buf[n++] = ','; if (nr_cpu_ids == total_cpus-1) - n += snprintf(&buf[n], len - n, "%u", nr_cpu_ids); + n += scnprintf(&buf[n], len - n, "%u", nr_cpu_ids); else - n += snprintf(&buf[n], len - n, "%u-%d", + n += scnprintf(&buf[n], len - n, "%u-%d", nr_cpu_ids, total_cpus-1); } - n += snprintf(&buf[n], len - n, "\n"); + n += scnprintf(&buf[n], len - n, "\n"); return n; } static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); -- 2.16.4