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 E5B18C46467 for ; Mon, 28 Mar 2022 11:37:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241808AbiC1Ldr (ORCPT ); Mon, 28 Mar 2022 07:33:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241741AbiC1LYK (ORCPT ); Mon, 28 Mar 2022 07:24:10 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB60956208; Mon, 28 Mar 2022 04:22:05 -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 ams.source.kernel.org (Postfix) with ESMTPS id 98693B80ED8; Mon, 28 Mar 2022 11:22:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B705C34100; Mon, 28 Mar 2022 11:22:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648466523; bh=Y9vz61kRi+0D0+pc4M6WJIazZc8SD+yi8M25hfH4qzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lcyYN0ntTvygFAwrXAX22nGm21Bv/D+IDjnsmugH4ZQr0xQmRMrt/QdEVQvASsHId CKo4ACmM7HAxRB8n9GMapGaHaLK0AQMO0vasuRzCt7XE4aXs+Wm3UDzF9tqXjKJNNC qX6vQq3tTXG0WJvWgIeUUm1ZvPWiXwki7UFY/GcIRqQBmowfG6I2LuSYL2Ikchpzba qWsCO/3tfQ6SGgnWLwOLWNY40Kdu1nK7iaaEv8l7u1zuRHjlOxYB882Q2L+F9IUHtZ zFsNSGwJApLu9DeHadsB7fniEYHHWxFNqg6QU9qJq1BjJlr64qqBgOkM6JKyheoMF4 uJ7vezlNRr78w== 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 5.15 14/29] loop: use sysfs_emit() in the sysfs xxx show() Date: Mon, 28 Mar 2022 07:21:16 -0400 Message-Id: <20220328112132.1555683-14-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220328112132.1555683-1-sashal@kernel.org> References: <20220328112132.1555683-1-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-kernel@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 92f9d32bfae5..8cba10aafadb 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -844,33 +844,33 @@ 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