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 BCE57C433EF for ; Mon, 28 Mar 2022 11:31:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241479AbiC1Lcl (ORCPT ); Mon, 28 Mar 2022 07:32:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241489AbiC1Lb2 (ORCPT ); Mon, 28 Mar 2022 07:31:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CED1A57499; Mon, 28 Mar 2022 04:24:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 262B360F43; Mon, 28 Mar 2022 11:24:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFB69C340ED; Mon, 28 Mar 2022 11:24:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648466661; bh=rLsO+ntsnTh0EzAnd/PjkFHrU+ojDgLX96KW1jxcRh8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z8BiODu4WuPordFkxBrJ1pg0wWczddBALNfUnSTZgqTgfLAYPDoODxiOBgCT5H6jX Bh7i9pyldUdgrwXyu/E3xsGyPtino8wEKopRNrxlkZxZ+4pxfawKWrDU/AFN5mRiXK Ki1biKUxdgIqG7MQi4X+vYBwBSf+5Qsoa1Cjju1j2LxQk/AP9UPfKgPU+vWVxb3AaM PvdsZAmduIoQywIkZQlYBSBBULWZqCgJxRY5g5JKQfo+wg8TcWCmOvqWyo6lz2mTrQ DOuA7Oc0zIkpvE8BusrrWeBaKFfTShd3GTIK+LLXdp73cv65U+kIkc1ahNJM4vBvIB 1hLhUQojSM9+Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chaitanya Kulkarni , Himanshu Madhani , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 02/12] loop: use sysfs_emit() in the sysfs xxx show() Date: Mon, 28 Mar 2022 07:24:07 -0400 Message-Id: <20220328112417.1556946-2-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220328112417.1556946-1-sashal@kernel.org> References: <20220328112417.1556946-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Chaitanya Kulkarni [ Upstream commit b27824d31f09ea7b4a6ba2c1b18bd328df3e8bed ] sprintf does not know the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content and it's possible to overrun the PAGE_SIZE buffer length. Use a generic sysfs_emit function that knows the size of the temporary buffer and ensures that no overrun is done for offset attribute in loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Himanshu Madhani Link: https://lore.kernel.org/r/20220215213310.7264-2-kch@nvidia.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/loop.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 19042b42a8ba..c31a76485c9c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -795,33 +795,33 @@ static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) { - return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); + return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_offset); } static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) { - return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); + return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); } static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) { int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); - return sprintf(buf, "%s\n", autoclear ? "1" : "0"); + return sysfs_emit(buf, "%s\n", autoclear ? "1" : "0"); } static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) { int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); - return sprintf(buf, "%s\n", partscan ? "1" : "0"); + return sysfs_emit(buf, "%s\n", partscan ? "1" : "0"); } static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf) { int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO); - return sprintf(buf, "%s\n", dio ? "1" : "0"); + return sysfs_emit(buf, "%s\n", dio ? "1" : "0"); } LOOP_ATTR_RO(backing_file); -- 2.34.1