From patchwork Thu Feb 18 17:50:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bodo Stroesser X-Patchwork-Id: 12094033 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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 94438C433DB for ; Thu, 18 Feb 2021 19:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 382FB64EB4 for ; Thu, 18 Feb 2021 19:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233490AbhBRTOU (ORCPT ); Thu, 18 Feb 2021 14:14:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230442AbhBRRvk (ORCPT ); Thu, 18 Feb 2021 12:51:40 -0500 Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [IPv6:2a00:1450:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACAFBC0613D6; Thu, 18 Feb 2021 09:50:57 -0800 (PST) Received: by mail-ed1-x536.google.com with SMTP id l12so5468115edt.3; Thu, 18 Feb 2021 09:50:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=ivQkfVgsx4WZGsQoMHh5wg3U5BQ3QtJ3+c6FaZcc3oY=; b=QfoAJYjm7aYDJ/g4vcV2mJ14et0jiBhEZ/4xGS4mIuVyw0hSM37YTMSM2E9NQ66/GI MoiBmtfqSVX+aBD0/EoCYHPmjX4TiXZiS+XNaj5jtf1mgCyOVLaHx1tp3Lsumo6ZwJbw La/8rSd0V2P//IL+C9xozR2fdMDLm4agP+Gs9jrzNKf3oZkkwi0+izGf/3IxdU6GYYAO VqBOOPB0BotabYfLHMEexHq3hA/F8+5bVnl2mfFzfp3XS5TU7r2/WjGx4HA/H3rE9kxU 1DHuVxYWOfOYBecjFnqUIoXfO5qimxzF+yp4RPVI+jOnRxMoivnEhY4mcxIyp1MuhwD3 g+Aw== 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; bh=ivQkfVgsx4WZGsQoMHh5wg3U5BQ3QtJ3+c6FaZcc3oY=; b=IDIBrGaSD3U+u4B4ij6p+TnpK82KXrhEJ7HljL1rHvX80I9etd9CWL7reE0gyoRMwa 7X8gYmVEMHfTVVcxG5Eu1Vlz2eU2CmT5uL55C1LCh4f0WXh1BIV9EY6hKZkRpAJE2Isx SwsVHRunWdbqIOolorAyXQff91OnqU71i5zKvfb3DQ2oZkCAkxvR834sLGKfwr2sVXvR pJBs/pLcuPh6eZ37eQzpJVscGqfvGbMakHwnItI9wkTxl/0iWbcZU1h4EHKr3kn0fWJ4 YmVbHOQ+DHwWpesc3MhTls9vd3q0s0qB0DRbOvSTLcCYICNF10YRp2aGGYb5UBmRhxC7 urnQ== X-Gm-Message-State: AOAM5322RY0a4ZEerfdKMfX5Kb3aXhUzIi6a7gJ6JN+kiQ3QX9vTpxoI G8W4E6+DlmteQfkS36ijKlL0p+Lpyfc= X-Google-Smtp-Source: ABdhPJzLWCaqXJ8haxRabVrDPE4iIpRxR0FRcRbAG0M/L04sBm3bfUyRqzb++QJllW2S97/F0G0AMQ== X-Received: by 2002:a05:6402:2694:: with SMTP id w20mr5316533edd.200.1613670656488; Thu, 18 Feb 2021 09:50:56 -0800 (PST) Received: from localhost (ipbcc06d06.dynamic.kabel-deutschland.de. [188.192.109.6]) by smtp.gmail.com with ESMTPSA id k13sm2933118ejc.23.2021.02.18.09.50.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Feb 2021 09:50:56 -0800 (PST) From: Bodo Stroesser To: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, "Martin K. Petersen" Cc: Bodo Stroesser , Mike Christie Subject: [PATCH 0/2] scsi: target: tcmu: Fix memory leak Date: Thu, 18 Feb 2021 18:50:37 +0100 Message-Id: <20210218175039.7829-1-bostroesser@gmail.com> X-Mailer: git-send-email 2.12.3 Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org This small series applies to Martin's for-next. This is the third attempt to fix a severe memory leak in tcmu. Previous patches: https://lore.kernel.org/linux-scsi/20201218141534.9918-1-bostroesser@gmail.com/ and https://lore.kernel.org/linux-scsi/20210210194031.7422-1-bostroesser@gmail.com/ Tcmu's refcounting relies on tcmu_open and tcmu_release being called symmetrically by uio. But that is not true if userspace daemon holds the uio device open or mmap'ed while tcmu calls uio_unregister device. So refcount can stay above 0 for ever, which means that tcmu does not free resources of a tcmu device. In extreme cases the amount of memory leaked can be > 1 GB for a single destroyed tcmu device. This new patch series fixes the problem by moving refcounting from tcmu_open/tcmu_release to new vm_operations_struct::open/*::close handlers, which are called under all conditions. Bodo Stroesser (2): scsi: target: tcmu: Move some functions without code change scsi: target: tcmu: Fix memory leak caused by wrong uio usage drivers/target/target_core_user.c | 189 +++++++++++++++++++++----------------- 1 file changed, 106 insertions(+), 83 deletions(-) Reviewed-by: Mike Christie