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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A5FFC7EE2D for ; Sun, 4 Jun 2023 13:12:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231902AbjFDNMQ (ORCPT ); Sun, 4 Jun 2023 09:12:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229788AbjFDNMN (ORCPT ); Sun, 4 Jun 2023 09:12:13 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1622B8; Sun, 4 Jun 2023 06:12:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685884332; x=1717420332; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=dO9+hudmBeE13l32Rylh0J5QaZhOfbdLqdQbEuq7Ixc=; b=iXAUuG4aunE4Pky+EBDpPBfr+J6bAZFwYXMJ38YAKd4QXpAvDzQCXmxb ZTWvrLuLdPQV8kh5Xln0Ssvmt4mLq12I/5UdeRiKDxAwr36/TFAPdchMI CEkVg3w5N3NXdcyuoImJOuwzGKd3GKUdg5FPNEdJMafHdX98sE33nR9hJ G468H2BSCcafkaLlS0X8Tzd+J52TnerK7ce2AyHiDFw2N4VVr+/k1esQ6 PFbhiGIeNGxkZoHMpufXWw2DuOv/N/FKpP/V4z+fYPtXAYRaiWYfiTKJa o4i+m6ik2LV7B36exO+8EDZXp4+a50VjtH04LlnmAPjvLD6vgfU20UzPE A==; X-IronPort-AV: E=McAfee;i="6600,9927,10731"; a="422008643" X-IronPort-AV: E=Sophos;i="6.00,217,1681196400"; d="scan'208";a="422008643" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2023 06:12:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10731"; a="778251865" X-IronPort-AV: E=Sophos;i="6.00,217,1681196400"; d="scan'208";a="778251865" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga004.fm.intel.com with ESMTP; 04 Jun 2023 06:12:10 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id 2F082204; Sun, 4 Jun 2023 16:12:17 +0300 (EEST) From: Andy Shevchenko To: Andy Shevchenko , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linus Walleij Subject: [PATCH v1 1/2] pinctrl: Duplicate user memory in one go in pinmux_select() Date: Sun, 4 Jun 2023 16:12:14 +0300 Message-Id: <20230604131215.78847-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.40.0.1.gaa8946217a0b MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current code is suboptimal in three ways: 1) it explicitly terminates the string which is not needed; 2) it might provoke additional faults, because asked lenght might be bigger than the real one; 3) it consumes more than needed lines in the source. Instead of using kmalloc() + strncpy_from_user() + terminating, just utilize memdup_user_nul(). Signed-off-by: Andy Shevchenko --- drivers/pinctrl/pinmux.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 021382632608..2d2f3bd164d5 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -692,14 +692,9 @@ static ssize_t pinmux_select(struct file *file, const char __user *user_buf, if (len > PINMUX_SELECT_MAX) return -ENOMEM; - buf = kzalloc(PINMUX_SELECT_MAX, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - ret = strncpy_from_user(buf, user_buf, PINMUX_SELECT_MAX); - if (ret < 0) - goto exit_free_buf; - buf[len-1] = '\0'; + buf = memdup_user_nul(user_buf, len); + if (IS_ERR(buf)) + return PTR_ERR(buf); /* remove leading and trailing spaces of input buffer */ gname = strstrip(buf); -- 2.40.0.1.gaa8946217a0b