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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79761ECAAA1 for ; Mon, 31 Oct 2022 14:09:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230420AbiJaOJG (ORCPT ); Mon, 31 Oct 2022 10:09:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231519AbiJaOJE (ORCPT ); Mon, 31 Oct 2022 10:09:04 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CB5310B51 for ; Mon, 31 Oct 2022 07:08:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667225284; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ssV5tIbeaDdUb05cqYH6611+3Ll1a3abXRc3rHIdohQ=; b=JP6mjbAHnyhvk+zVpAl9acraC8CUuOKkpnKwYx5hau548BlDXcZOECOFdT5agzpqiCShRm c0NUnMQjKIRujrvBfh1JRmPERd0kbo7wXZqIjglTG7XaZGgiSf6VFrdyOm48g6hfeoycmf BuE3m10Qei8JeuTJoKtgfQWBfQ/B59U= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [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-500-Z08Maf4fOTmFY7vF07KYhQ-1; Mon, 31 Oct 2022 10:07:58 -0400 X-MC-Unique: Z08Maf4fOTmFY7vF07KYhQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 600063C0D84B; Mon, 31 Oct 2022 14:07:55 +0000 (UTC) Received: from T590 (ovpn-8-28.pek2.redhat.com [10.72.8.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 22B5A40C2066; Mon, 31 Oct 2022 14:07:50 +0000 (UTC) Date: Mon, 31 Oct 2022 22:07:45 +0800 From: Ming Lei To: Chen Jun Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, axboe@kernel.dk, will@kernel.org, xuqiang36@huawei.com Subject: Re: [PATCH] blk-mq: Fix kmemleak in blk_mq_init_allocated_queue Message-ID: References: <20221031031242.94107-1-chenjun102@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221031031242.94107-1-chenjun102@huawei.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 31, 2022 at 03:12:42AM +0000, Chen Jun wrote: > There is a kmemleak caused by modprobe null_blk.ko > > unreferenced object 0xffff8881acb1f000 (size 1024): > comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) > hex dump (first 32 bytes): > 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... > ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... > backtrace: > [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 > [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 > [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 > [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 > [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 > [<00000000d10c98c3>] 0xffffffffc450d69d > [<00000000b9299f48>] 0xffffffffc4538392 > [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 > [<00000000b389383b>] do_init_module+0x1a4/0x680 > [<0000000087cf3542>] load_module+0x6249/0x7110 > [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 > [<00000000fdcfff51>] do_syscall_64+0x35/0x80 > [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > That is because q->ma_ops is set to NULL before blk_release_queue is > called. > > blk_mq_init_queue_data > blk_mq_init_allocated_queue > blk_mq_realloc_hw_ctxs > for (i = 0; i < set->nr_hw_queues; i++) { > old_hctx = xa_load(&q->hctx_table, i); > if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] > if (!old_hctx) > break; > > xa_for_each_start(&q->hctx_table, j, hctx, j) > blk_mq_exit_hctx(q, set, hctx, j); [2] > > if (!q->nr_hw_queues) [3] > goto err_hctxs; > > err_exit: > q->mq_ops = NULL; [4] > > blk_put_queue > blk_release_queue > if (queue_is_mq(q)) [5] > blk_mq_release(q); > > [1]: blk_mq_alloc_and_init_hctx failed at i != 0. > [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and > will be cleaned up in blk_mq_release. > [3]: q->nr_hw_queues is 0. > [4]: Set q->mq_ops to NULL. > [5]: queue_is_mq returns false due to [4]. And blk_mq_release > will not be called. The hctxs in q->unused_hctx_list are leaked. > > To fix it, call blk_release_queue in exception path. > > Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed") > Signed-off-by: Yuan Can > Signed-off-by: Chen Jun Reviewed-by: Ming Lei Thanks, Ming