From patchwork Thu Aug 4 17:25:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Saurabh Singh Sengar X-Patchwork-Id: 12936540 X-Patchwork-Delegate: song@kernel.org 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 CB022C19F2A for ; Thu, 4 Aug 2022 17:26:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238146AbiHDR0G (ORCPT ); Thu, 4 Aug 2022 13:26:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232682AbiHDR0G (ORCPT ); Thu, 4 Aug 2022 13:26:06 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E8883635E; Thu, 4 Aug 2022 10:26:02 -0700 (PDT) Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 8047E20FFD77; Thu, 4 Aug 2022 10:26:02 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8047E20FFD77 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1659633962; bh=pbGMSvkNq0n5vGmLdQjGupj2fHoF+I2KZEXvzIDUlzc=; h=From:To:Subject:Date:From; b=s78aQy+ZhSAflPOZy70UO2ugs+JX+x0/vVUnf8RGsQwBkijJuD3T6GC4YE1DlD/br sXj8VmWo896ArVGRuNzDY1KMZQbfnkzfAIroo/tenuU56nm+vwb3NVSbw4taV/HiPg 7UagKHbUppnVoG/+YgkhhvYgeTxQT8ldfiNMP1eU= From: Saurabh Sengar To: song@kernel.org, shli@fb.com, neilb@suse.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, ssengar@microsoft.com, mikelley@microsoft.com Subject: [PATCH] md : Replace snprintf with scnprintf Date: Thu, 4 Aug 2022 10:25:58 -0700 Message-Id: <1659633958-32756-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Current code produces a warning as shown below when total characters in the constituent block device names plus the slashes exceeds 200. snprintf() returns the number of characters generated from the given input, which could cause the expression “200 – len” to wrap around to a large positive number. Fix this by using scnprintf() instead, which returns the actual number of characters written into the buffer. [ 1513.267938] ------------[ cut here ]------------ [ 1513.267943] WARNING: CPU: 15 PID: 37247 at /lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510 [ 1513.267944] Modules linked in: [ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu [ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510 <-snip-> [ 1513.267982] Call Trace: [ 1513.267986] snprintf+0x45/0x70 [ 1513.267990] ? disk_name+0x71/0xa0 [ 1513.267993] dump_zones+0x114/0x240 [raid0] [ 1513.267996] ? _cond_resched+0x19/0x40 [ 1513.267998] raid0_run+0x19e/0x270 [raid0] [ 1513.268000] md_run+0x5e0/0xc50 [ 1513.268003] ? security_capable+0x3f/0x60 [ 1513.268005] do_md_run+0x19/0x110 [ 1513.268006] md_ioctl+0x195e/0x1f90 [ 1513.268007] blkdev_ioctl+0x91f/0x9f0 [ 1513.268010] block_ioctl+0x3d/0x50 [ 1513.268012] do_vfs_ioctl+0xa9/0x640 [ 1513.268014] ? __fput+0x162/0x260 [ 1513.268016] ksys_ioctl+0x75/0x80 [ 1513.268017] __x64_sys_ioctl+0x1a/0x20 [ 1513.268019] do_syscall_64+0x5e/0x200 [ 1513.268021] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()") Signed-off-by: Saurabh Sengar Reviewed-by: Michael Kelley Acked-by: Guoqing Jiang --- drivers/md/raid0.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index b21e101..b6f0fc1 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -48,7 +48,7 @@ static void dump_zones(struct mddev *mddev) int len = 0; for (k = 0; k < conf->strip_zone[j].nb_dev; k++) - len += snprintf(line+len, 200-len, "%s%s", k?"/":"", + len += scnprintf(line+len, 200-len, "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); pr_debug("md: zone%d=[%s]\n", j, line);