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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ED0AC2BB85 for ; Thu, 16 Apr 2020 13:42:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EC292222C for ; Thu, 16 Apr 2020 13:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044562; bh=4FfjHUzoXOQuHsFmCwjdJHNFyyAOjk/AM8IR/EFRMnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IWIY2nGmROI/X1mX6GcRQtx0EKQHRRtVjPW1BEaZBwL6Y99KmeEvEjO9D+xkrE43t KbgJ1TuVTJ0SBR46EnjBcliPDXp3CNzFg1JcgPF/z7KvvxO8sjz1fy+gseFJRFQB5k oSUXIUgNULKoSJSJQFOQdiPZP/XxmTkRkBbUVP8E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441554AbgDPNmk (ORCPT ); Thu, 16 Apr 2020 09:42:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:44106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2896693AbgDPNdN (ORCPT ); Thu, 16 Apr 2020 09:33:13 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 28838208E4; Thu, 16 Apr 2020 13:33:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043993; bh=4FfjHUzoXOQuHsFmCwjdJHNFyyAOjk/AM8IR/EFRMnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o9Ddqge7LXPj3+I0Xjsq0u+Kr4FCf4fILyg5YhL/bcCg109yUmxFcrMhpSaZIq7XI 3txsxHA6pvzeZ7lknfNy1a4+F5nth55gos4UGPI4Xi2SPW8Jp+5cS6vyZGK8f42bQc DE/UANEY5K3EKVqwpl7uh+VGpZ+Jpc4bAz4VsJNk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Chaitanya Kulkarni , Johannes Thumshirn , Hannes Reinecke , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 5.5 038/257] null_blk: Handle null_add_dev() failures properly Date: Thu, 16 Apr 2020 15:21:29 +0200 Message-Id: <20200416131330.705406807@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.891903893@linuxfoundation.org> References: <20200416131325.891903893@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bart Van Assche [ Upstream commit 9b03b713082a31a5b90e0a893c72aa620e255c26 ] If null_add_dev() fails then null_del_dev() is called with a NULL argument. Make null_del_dev() handle this scenario correctly. This patch fixes the following KASAN complaint: null-ptr-deref in null_del_dev+0x28/0x280 [null_blk] Read of size 8 at addr 0000000000000000 by task find/1062 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0x99 kasan_report+0x16/0x20 __asan_load8+0x58/0x90 null_del_dev+0x28/0x280 [null_blk] nullb_group_drop_item+0x7e/0xa0 [null_blk] client_drop_item+0x53/0x80 [configfs] configfs_rmdir+0x395/0x4e0 [configfs] vfs_rmdir+0xb6/0x220 do_rmdir+0x238/0x2c0 __x64_sys_unlinkat+0x75/0x90 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Bart Van Assche Reviewed-by: Chaitanya Kulkarni Cc: Johannes Thumshirn Cc: Hannes Reinecke Cc: Ming Lei Cc: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/null_blk_main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 97bb53d7fa348..635904bfcf777 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1432,7 +1432,12 @@ static void cleanup_queues(struct nullb *nullb) static void null_del_dev(struct nullb *nullb) { - struct nullb_device *dev = nullb->dev; + struct nullb_device *dev; + + if (!nullb) + return; + + dev = nullb->dev; ida_simple_remove(&nullb_indexes, nullb->index); -- 2.20.1