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 C0302C10F25 for ; Wed, 11 Mar 2020 07:13:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95D2E21D56 for ; Wed, 11 Mar 2020 07:13:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728349AbgCKHNo (ORCPT ); Wed, 11 Mar 2020 03:13:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:35662 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbgCKHNo (ORCPT ); Wed, 11 Mar 2020 03:13:44 -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 98773AF4E; Wed, 11 Mar 2020 07:13:42 +0000 (UTC) From: Takashi Iwai To: "Rafael J . Wysocki" , Viresh Kumar Cc: linux-pm@vger.kernel.org Subject: [PATCH] cpufreq: Use scnprintf() for avoiding potential buffer overflow Date: Wed, 11 Mar 2020 08:13:41 +0100 Message-Id: <20200311071341.4339-1-tiwai@suse.de> X-Mailer: git-send-email 2.16.4 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@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/cpufreq/cpufreq_stats.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index f9bcf0f3ea30..94d959a8e954 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -90,35 +90,35 @@ static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) if (policy->fast_switch_enabled) return 0; - len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); - len += snprintf(buf + len, PAGE_SIZE - len, " : "); + len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n"); + len += scnprintf(buf + len, PAGE_SIZE - len, " : "); for (i = 0; i < stats->state_num; i++) { if (len >= PAGE_SIZE) break; - len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", + len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ", stats->freq_table[i]); } if (len >= PAGE_SIZE) return PAGE_SIZE; - len += snprintf(buf + len, PAGE_SIZE - len, "\n"); + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); for (i = 0; i < stats->state_num; i++) { if (len >= PAGE_SIZE) break; - len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", + len += scnprintf(buf + len, PAGE_SIZE - len, "%9u: ", stats->freq_table[i]); for (j = 0; j < stats->state_num; j++) { if (len >= PAGE_SIZE) break; - len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", + len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ", stats->trans_table[i*stats->max_state+j]); } if (len >= PAGE_SIZE) break; - len += snprintf(buf + len, PAGE_SIZE - len, "\n"); + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); } if (len >= PAGE_SIZE) { -- 2.16.4