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=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 ADF44C10DCE for ; Tue, 10 Mar 2020 04:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95FF72467D for ; Tue, 10 Mar 2020 04:26:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726170AbgCJE0n (ORCPT ); Tue, 10 Mar 2020 00:26:43 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:38949 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726018AbgCJE0n (ORCPT ); Tue, 10 Mar 2020 00:26:43 -0400 Received: by mail-pg1-f196.google.com with SMTP id s2so5728516pgv.6 for ; Mon, 09 Mar 2020 21:26:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IzlOKrcv2Oe/XzzP6feQVhs2X9Bl/DPBL5XHFlPOVT4=; b=sw+iwCkgVK55onAxkg0Y11mpHW/8B1iUNKAH4PBREFT716vkP+yQgX3E5KpbjRLzw9 90FiZDFtQsjInpsPrgLN/Fpu/rKcSQLX2uPveZ8en1PG/399WUpN3LCuhv/wms1XsAM/ amPMlMSUFUzocGUp9ZlUQWJ6uhiKZekr7AseCQ6YD3Jj9ZY503vSNL/qPqyRS3StI7ZF iy1jtnE9Fq21FsF4+4k39F8XRwFajwwavkOP8+DGL1yaI/823pOR1222wBE8mswVdj/4 ChMTuX3Qli0YK9k9WeUJ7+hvW1jGVbSGM5zW+uZkzHpvZawyhAvR4mU+lEH+FQgLsP8E N95A== X-Gm-Message-State: ANhLgQ1kXbrLxljIlRVeGQlQYcUS1BFwV+eXjW4nUN6CnZKxgZAFrcib szMsHj64Fn2aU8HdeHKCPLU= X-Google-Smtp-Source: ADFU+vs7YOFt7+yv4k8GafzbTijftZDi38oKlPg+vmxJXW/t16zogIi98+gR7awjfPU0hmNM5wVsJw== X-Received: by 2002:a62:64c9:: with SMTP id y192mr2877289pfb.26.1583814402023; Mon, 09 Mar 2020 21:26:42 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:c0e4:71da:7a83:2357]) by smtp.gmail.com with ESMTPSA id l189sm5963240pga.64.2020.03.09.21.26.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2020 21:26:41 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Christoph Hellwig , Ming Lei , Hannes Reinecke , Johannes Thumshirn , Chaitanya Kulkarni Subject: [PATCH v4 7/8] null_blk: Handle null_add_dev() failures properly Date: Mon, 9 Mar 2020 21:26:22 -0700 Message-Id: <20200310042623.20779-8-bvanassche@acm.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310042623.20779-1-bvanassche@acm.org> References: <20200310042623.20779-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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 Cc: Christoph Hellwig Cc: Ming Lei Cc: Hannes Reinecke Cc: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Signed-off-by: Bart Van Assche --- 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 80d3dcb8722c..d21c82c8863f 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1469,7 +1469,12 @@ static const struct blk_mq_ops null_mq_ops = { 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);