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 B50EDC7619A for ; Wed, 15 Mar 2023 11:31:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231552AbjCOLbq (ORCPT ); Wed, 15 Mar 2023 07:31:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230356AbjCOLbm (ORCPT ); Wed, 15 Mar 2023 07:31:42 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1937864846; Wed, 15 Mar 2023 04:31:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678879902; x=1710415902; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=CbKC9In0sfgAFhGmEkzB7Bb+JmElN2MpqrLq/60tyc4=; b=ElAxf5JwDWlsUz4WnDO0m9NyEmkAV2NOUUFD8qSfgU5WNco8iswrNDK/ JxrlzVeaTH3ohGiyvpG9OqH6PnQPETgTErrS1IJTHRipzvVjqHA4xHOsW u/H3MKTPE9LFLn3n2T1ailbwqD5u7q+ecvpQ+bqdcnga9TtLOP/VbdSle Bb7G7iE5RBCnXSmP02CHBt2U1dvgbFoRwkeIWjUVKffnx1tzEe9cug62j b7Pn1tNrutSldOoKv2sOzMOfV2TpMRczu252huVVkppqOS/75UCXhcjDJ WhVjNtEfeWuHmoXcUneeQHmxR6GVBLY4p3PHXzGI9xRzdGe1zURM6iKeQ A==; X-IronPort-AV: E=McAfee;i="6500,9779,10649"; a="317330268" X-IronPort-AV: E=Sophos;i="5.98,262,1673942400"; d="scan'208";a="317330268" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2023 04:31:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10649"; a="925310514" X-IronPort-AV: E=Sophos;i="5.98,262,1673942400"; d="scan'208";a="925310514" Received: from nopopovi-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.33.48]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2023 04:31:38 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id BB81D10CC9F; Wed, 15 Mar 2023 14:31:35 +0300 (+03) From: "Kirill A. Shutemov" To: Andrew Morton , Mel Gorman , Vlastimil Babka , David Hildenbrand Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Denis Efremov Subject: [PATCH 03/10] floppy: Fix MAX_ORDER usage Date: Wed, 15 Mar 2023 14:31:26 +0300 Message-Id: <20230315113133.11326-4-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230315113133.11326-1-kirill.shutemov@linux.intel.com> References: <20230315113133.11326-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org MAX_ORDER is not inclusive: the maximum allocation order buddy allocator can deliver is MAX_ORDER-1. Fix MAX_ORDER usage in floppy code. Also allocation buffer exactly PAGE_SIZE << MAX_ORDER bytes is okay. Fix MAX_LEN check. Signed-off-by: Kirill A. Shutemov Cc: Denis Efremov --- drivers/block/floppy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 487840e3564d..90d2dfb6448e 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3079,7 +3079,7 @@ static void raw_cmd_free(struct floppy_raw_cmd **ptr) } } -#define MAX_LEN (1UL << MAX_ORDER << PAGE_SHIFT) +#define MAX_LEN (1UL << (MAX_ORDER - 1) << PAGE_SHIFT) static int raw_cmd_copyin(int cmd, void __user *param, struct floppy_raw_cmd **rcmd) @@ -3108,7 +3108,7 @@ static int raw_cmd_copyin(int cmd, void __user *param, ptr->resultcode = 0; if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) { - if (ptr->length <= 0 || ptr->length >= MAX_LEN) + if (ptr->length <= 0 || ptr->length > MAX_LEN) return -EINVAL; ptr->kernel_data = (char *)fd_dma_mem_alloc(ptr->length); fallback_on_nodma_alloc(&ptr->kernel_data, ptr->length); -- 2.39.2