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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 4C857C2BB1D for ; Fri, 10 Apr 2020 03:50:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 230E320BED for ; Fri, 10 Apr 2020 03:50:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490652; bh=qjQazNArWeNAA7WhoMO2JjCBRNq1jnnEvi3X36L9kf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MiAAuU6WRCCYBDz3JkBecZZDqASzbDLd4/s4yZGyWK+dEeClhlB15xBy0c36Q5Cz/ 8A0nixosTME7z5YUbKCh1OajMgvOw6c7qCsNFrM+ciGjpR4+136PPsUy6u+RI4F3Io uUc+liJbKCz5zw6LOz6pBRo/Tii2DDreU0s5+VqQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728338AbgDJDuu (ORCPT ); Thu, 9 Apr 2020 23:50:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:35584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728311AbgDJDur (ORCPT ); Thu, 9 Apr 2020 23:50:47 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A687620CC7; Fri, 10 Apr 2020 03:50:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490647; bh=qjQazNArWeNAA7WhoMO2JjCBRNq1jnnEvi3X36L9kf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zlc9A6naEWWqI+pC1nN5iyJ6b5AMh7Ll92R2DSc01j1kvTcIE7kVIprmkiwxRrkVr qZke5JylxOF3oCbipC2NyVis+y4XyUArYQ4LkKV8IjtyyYWDB33U9TDSaL3hyQX0tA pNRhf1ehQ2I3aISUCeKwXLYxB7lqf9aHtlygI9J8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bart Van Assche , Chaitanya Kulkarni , Johannes Thumshirn , Hannes Reinecke , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 02/22] null_blk: Handle null_add_dev() failures properly Date: Thu, 9 Apr 2020 23:50:24 -0400 Message-Id: <20200410035044.9698-2-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410035044.9698-1-sashal@kernel.org> References: <20200410035044.9698-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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