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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25107C43217 for ; Mon, 27 Sep 2021 17:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C732611F0 for ; Mon, 27 Sep 2021 17:24:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237902AbhI0R0M (ORCPT ); Mon, 27 Sep 2021 13:26:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:41376 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237893AbhI0RYB (ORCPT ); Mon, 27 Sep 2021 13:24:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9193B613C8; Mon, 27 Sep 2021 17:15:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632762917; bh=M5gpKuARtFe9V4AjmZU4muHT5/fSXcGFswy7yPukRvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xrKhC9/K4f7C/jY2e4czrKUutBHcx8T73s/Gh2ioqbUlN8aY2WZknjDzsg55mTs+M hK+NtPJ7Iuh7H+ZeIUhsEhSkh/o2rOqhPYQotArWwcoL6WdL5kcuguaQ3EgicxKCn3 dsR/6RACDMhdMsMa8lPQ+7GSCXLzNmgUTJ8qXSgU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Daniel Lezcano , Sasha Levin Subject: [PATCH 5.14 100/162] thermal/core: Potential buffer overflow in thermal_build_list_of_policies() Date: Mon, 27 Sep 2021 19:02:26 +0200 Message-Id: <20210927170236.910960528@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927170233.453060397@linuxfoundation.org> References: <20210927170233.453060397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit 1bb30b20b49773369c299d4d6c65227201328663 ] After printing the list of thermal governors, then this function prints a newline character. The problem is that "size" has not been updated after printing the last governor. This means that it can write one character (the NUL terminator) beyond the end of the buffer. Get rid of the "size" variable and just use "PAGE_SIZE - count" directly. Fixes: 1b4f48494eb2 ("thermal: core: group functions related to governor handling") Signed-off-by: Dan Carpenter Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20210916131342.GB25094@kili Signed-off-by: Sasha Levin --- drivers/thermal/thermal_core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 97ef9b040b84..51374f4e1cca 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -222,15 +222,14 @@ int thermal_build_list_of_policies(char *buf) { struct thermal_governor *pos; ssize_t count = 0; - ssize_t size = PAGE_SIZE; mutex_lock(&thermal_governor_lock); list_for_each_entry(pos, &thermal_governor_list, governor_list) { - size = PAGE_SIZE - count; - count += scnprintf(buf + count, size, "%s ", pos->name); + count += scnprintf(buf + count, PAGE_SIZE - count, "%s ", + pos->name); } - count += scnprintf(buf + count, size, "\n"); + count += scnprintf(buf + count, PAGE_SIZE - count, "\n"); mutex_unlock(&thermal_governor_lock); -- 2.33.0