From patchwork Mon Jul 24 12:02:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Natalenko X-Patchwork-Id: 13324526 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 369E9C001DE for ; Mon, 24 Jul 2023 12:03:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230147AbjGXMDi (ORCPT ); Mon, 24 Jul 2023 08:03:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229486AbjGXMDe (ORCPT ); Mon, 24 Jul 2023 08:03:34 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C067E6D for ; Mon, 24 Jul 2023 05:02:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690200168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lSRQBULx+TvRi9w0R85wybLn1zR6qk9EVDsaRk1ameQ=; b=Gzqf5USKNErEseoPd2WK/leomC139OmqcezyGpkfRPd3T8fVRRcBY3vi6Hb2MKOhX+hRZ3 jiG2I8gfiq3DoOrpte5tGEGolpOrbsyeQSUFSWyoI/67GD7h4+EQ8R3xAxJrCnRpdIX495 MDcmPlHmDxzWuk0kf9pUIvlFeFv3hnI= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-665-LkaPnEg9PgulEKUeZ7-pKw-1; Mon, 24 Jul 2023 08:02:43 -0400 X-MC-Unique: LkaPnEg9PgulEKUeZ7-pKw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1FA3A3827907; Mon, 24 Jul 2023 12:02:43 +0000 (UTC) Received: from localhost (dhcp-10-40-5-80.brq.redhat.com [10.40.5.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id C64B6C2C856; Mon, 24 Jul 2023 12:02:42 +0000 (UTC) From: Oleksandr Natalenko To: linux-kernel@vger.kernel.org Cc: linux-scsi@vger.kernel.org, Saurav Kashyap , Javed Hasan , GR-QLogic-Storage-Upstream@marvell.com, "James E.J. Bottomley" , "Martin K. Petersen" , Jozef Bacik , Laurence Oberman , Rob Evers Subject: [RFC PATCH 1/3] scsi: qedf: do not touch __user pointer in qedf_dbg_stop_io_on_error_cmd_read() directly Date: Mon, 24 Jul 2023 14:02:39 +0200 Message-ID: <20230724120241.40495-2-oleksandr@redhat.com> In-Reply-To: <20230724120241.40495-1-oleksandr@redhat.com> References: <20230724120241.40495-1-oleksandr@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The qedf_dbg_stop_io_on_error_cmd_read() function invokes sprintf() directly on a __user pointer, which may crash the kernel. Avoid doing that by using a small on-stack buffer for sprintf() and then calling simple_read_from_buffer() which does a proper copy_to_user() call. Signed-off-by: Oleksandr Natalenko --- drivers/scsi/qedf/qedf_debugfs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/qedf/qedf_debugfs.c b/drivers/scsi/qedf/qedf_debugfs.c index a3ed681c8ce3f..4d1b99569d490 100644 --- a/drivers/scsi/qedf/qedf_debugfs.c +++ b/drivers/scsi/qedf/qedf_debugfs.c @@ -185,18 +185,17 @@ qedf_dbg_stop_io_on_error_cmd_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { int cnt; + char cbuf[7]; struct qedf_dbg_ctx *qedf_dbg = (struct qedf_dbg_ctx *)filp->private_data; struct qedf_ctx *qedf = container_of(qedf_dbg, struct qedf_ctx, dbg_ctx); QEDF_INFO(qedf_dbg, QEDF_LOG_DEBUGFS, "entered\n"); - cnt = sprintf(buffer, "%s\n", + cnt = sprintf(cbuf, "%s\n", qedf->stop_io_on_error ? "true" : "false"); - cnt = min_t(int, count, cnt - *ppos); - *ppos += cnt; - return cnt; + return simple_read_from_buffer(buffer, count, ppos, cbuf, cnt); } static ssize_t