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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 08D5CC31E57 for ; Mon, 17 Jun 2019 11:17:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDF222084D for ; Mon, 17 Jun 2019 11:17:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbfFQLRQ (ORCPT ); Mon, 17 Jun 2019 07:17:16 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:37082 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727599AbfFQLRQ (ORCPT ); Mon, 17 Jun 2019 07:17:16 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 3F48C621E47ACC282D02; Mon, 17 Jun 2019 19:17:13 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Mon, 17 Jun 2019 19:17:02 +0800 From: John Garry To: CC: , , , , , John Garry Subject: [PATCH v3] bus: hisi_lpc: Avoid use-after-free from probe failure Date: Mon, 17 Jun 2019 19:15:48 +0800 Message-ID: <1560770148-57960-1-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If, after registering a logical PIO range, the driver probe later fails, the logical PIO range memory will be released automatically. This causes an issue, in that the logical PIO range is not unregistered and the released range memory may be later referenced. As an interim fix, allocate the logical PIO range with kzalloc() to avoid this memory being freed. Further memory will not be leaked from later attempts to probe the driver, as any attempts to allocate logical PIO ranges will fail, and we would release the 'range' memory. The correct fix for this problem would be to tear down what had been setup during the probe, i.e. unregister the logical PIO range, but this is not supported. Support for unregistering logical PIO ranges will need be to added in future. Fixes: adf38bb0b5956 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings") Signed-off-by: John Garry --- Change in v2: - update commit message Change to v1: - add comment, as advised by Joe Perches diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 19d7b6ff2f17..5f0130a693fe 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -599,7 +599,8 @@ static int hisi_lpc_probe(struct platform_device *pdev) if (IS_ERR(lpcdev->membase)) return PTR_ERR(lpcdev->membase); - range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL); + /* Logical PIO may reference 'range' memory even if the probe fails */ + range = kzalloc(sizeof(*range), GFP_KERNEL); if (!range) return -ENOMEM; @@ -610,6 +611,7 @@ static int hisi_lpc_probe(struct platform_device *pdev) ret = logic_pio_register_range(range); if (ret) { dev_err(dev, "register IO range failed (%d)!\n", ret); + kfree(range); return ret; } lpcdev->io_host = range; -- 2.17.1