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,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 2C21FC55189 for ; Wed, 22 Apr 2020 10:53:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 097742076E for ; Wed, 22 Apr 2020 10:53:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587552819; bh=qjQazNArWeNAA7WhoMO2JjCBRNq1jnnEvi3X36L9kf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t7p63ITtJ2MP52Zf6/1oQcHwdPoX2ZjnvM4KW4l6Sj47kUAd4WKhyiG4tIiEEsug/ wSscHUPV9CLFslZKvrNNZmPyt++OEu+L1X+78mR/yBMnndNa/6czDsjdlf3xK/fZmK We2mtL9gR4WpV5wWo/SNdegBBt0IkvetB7gzQPZA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728753AbgDVKIq (ORCPT ); Wed, 22 Apr 2020 06:08:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:34426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728738AbgDVKIj (ORCPT ); Wed, 22 Apr 2020 06:08:39 -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 25E482071E; Wed, 22 Apr 2020 10:08:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550118; bh=qjQazNArWeNAA7WhoMO2JjCBRNq1jnnEvi3X36L9kf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mCiitB/uS0awRiAE8FChAOPgS9rav8iNRODr7x0FSJBq8W78dPxkZgnmiQ7xLZxJa sULuFGZSggJb+USrg7XqwcdKRRIQRK8WGL3Iur9zkF4vJUz8GuaD9d2sZyryYhm9Zg Il8rnuu4ovlzaAMgSMDTThYmCBiiB4YgiIkcd8TY= 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 4.14 009/199] null_blk: Handle null_add_dev() failures properly Date: Wed, 22 Apr 2020 11:55:35 +0200 Message-Id: <20200422095059.184127267@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095057.806111593@linuxfoundation.org> References: <20200422095057.806111593@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.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index e9776ca0996b0..b4078901dbcb9 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1593,7 +1593,12 @@ static void null_nvm_unregister(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