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 BC175C6370B for ; Wed, 7 Dec 2022 22:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbiLGWwa (ORCPT ); Wed, 7 Dec 2022 17:52:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229470AbiLGWw3 (ORCPT ); Wed, 7 Dec 2022 17:52:29 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F012685662; Wed, 7 Dec 2022 14:52:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670453549; x=1701989549; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EHXrUzFqhtjrtp+2R9Fafu9ntu7u1UaPLUSfczdzlWE=; b=DClaJA0v7HFjSN6HKpvW/VK4O6LjOB9I+4aLVx/TRXAiBPaoANbEFI0C VCbQ2DhNeEMXvSfpsAZgk9DhN+qXRKsD8O+h5mihcjgQfBullDQkNr1II qQuy0+WSu5ulYiqTzaFxYG3a1jX8amIcOnLyIM1mRZs1MjiSpQ/xE3HdA 3UMcksGv5ECPBJsMpXi0OHjNvQmdQE1Stssgg4n7YNL62UXE1C5x/2cdb FqoiS7/36yPQzwKkt/7M1EGd7ReDXZyQbHrRktmgikYmTuWUWJhJOvWdB 7MTTndxNIB7Trt8I72fCoOiGLiC2NF0MXpNJ+hihzRTanQHbiJxTig7df Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10554"; a="300439516" X-IronPort-AV: E=Sophos;i="5.96,225,1665471600"; d="scan'208";a="300439516" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2022 14:52:27 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10554"; a="646781161" X-IronPort-AV: E=Sophos;i="5.96,225,1665471600"; d="scan'208";a="646781161" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2022 14:52:27 -0800 From: Reinette Chatre To: fenghua.yu@intel.com, dave.jiang@intel.com, vkoul@kernel.org, dmaengine@vger.kernel.org Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH V2 2/3] dmaengine: idxd: Prevent use after free on completion memory Date: Wed, 7 Dec 2022 14:52:21 -0800 Message-Id: <6c4657d9cff0a0a00501a7b928297ac966e9ec9d.1670452419.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On driver unload any pending descriptors are flushed at the time the interrupt is freed: idxd_dmaengine_drv_remove() -> drv_disable_wq() -> idxd_wq_free_irq() -> idxd_flush_pending_descs(). If there are any descriptors present that need to be flushed this flow triggers a "not present" page fault as below: BUG: unable to handle page fault for address: ff391c97c70c9040 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page The address that triggers the fault is the address of the descriptor that was freed moments earlier via: drv_disable_wq()->idxd_wq_free_resources() Fix the use after free by freeing the descriptors after any possible usage. This is done after idxd_wq_reset() to ensure that the memory remains accessible during possible completion writes by the device. Fixes: 63c14ae6c161 ("dmaengine: idxd: refactor wq driver enable/disable operations") Suggested-by: Dave Jiang Signed-off-by: Reinette Chatre Reviewed-by: Dave Jiang Reviewed-by: Fenghua Yu Cc: stable@vger.kernel.org --- Changes since V1: - Add Dave and Fenghua's Reviewed-by tags. - cc stable team (Fenghua). drivers/dma/idxd/device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c index fcd03d29a941..b4d7bb923a40 100644 --- a/drivers/dma/idxd/device.c +++ b/drivers/dma/idxd/device.c @@ -1408,11 +1408,11 @@ void drv_disable_wq(struct idxd_wq *wq) dev_warn(dev, "Clients has claim on wq %d: %d\n", wq->id, idxd_wq_refcount(wq)); - idxd_wq_free_resources(wq); idxd_wq_unmap_portal(wq); idxd_wq_drain(wq); idxd_wq_free_irq(wq); idxd_wq_reset(wq); + idxd_wq_free_resources(wq); percpu_ref_exit(&wq->wq_active); wq->type = IDXD_WQT_NONE; wq->client_count = 0; -- 2.34.1