From patchwork Wed Oct 13 11:41:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Hai X-Patchwork-Id: 12556487 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4602C433EF for ; Wed, 13 Oct 2021 17:35:50 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 510A8610EA for ; Wed, 13 Oct 2021 17:35:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 510A8610EA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C82816E0EA; Wed, 13 Oct 2021 17:35:43 +0000 (UTC) X-Greylist: delayed 963 seconds by postgrey-1.36 at gabe; Wed, 13 Oct 2021 11:58:37 UTC Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by gabe.freedesktop.org (Postfix) with ESMTPS id C5FD06EA2F for ; Wed, 13 Oct 2021 11:58:37 +0000 (UTC) Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4HTrFf2Mvjz1DHNt; Wed, 13 Oct 2021 19:40:54 +0800 (CST) Received: from kwepemm600001.china.huawei.com (7.193.23.3) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Wed, 13 Oct 2021 19:42:31 +0800 Received: from huawei.com (10.175.104.82) by kwepemm600001.china.huawei.com (7.193.23.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Wed, 13 Oct 2021 19:42:30 +0800 From: Wang Hai To: , , , , , CC: , Subject: [PATCH] drm: fix null-ptr-deref in drm_dev_init_release() Date: Wed, 13 Oct 2021 19:41:39 +0800 Message-ID: <20211013114139.4042207-1-wanghai38@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600001.china.huawei.com (7.193.23.3) X-CFilter-Loop: Reflected X-Mailman-Approved-At: Wed, 13 Oct 2021 17:35:42 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" I got a null-ptr-deref report: [drm:drm_dev_init [drm]] *ERROR* Cannot allocate anonymous inode: -12 ================================================================== BUG: KASAN: null-ptr-deref in iput+0x3c/0x4a0 ... Call Trace: dump_stack_lvl+0x6c/0x8b kasan_report.cold+0x64/0xdb __asan_load8+0x69/0x90 iput+0x3c/0x4a0 drm_dev_init_release+0x39/0xb0 [drm] drm_managed_release+0x158/0x2d0 [drm] drm_dev_init+0x3a7/0x4c0 [drm] __devm_drm_dev_alloc+0x55/0xd0 [drm] mi0283qt_probe+0x8a/0x2b5 [mi0283qt] spi_probe+0xeb/0x130 ... entry_SYSCALL_64_after_hwframe+0x44/0xae If drm_fs_inode_new() fails in drm_dev_init(), dev->anon_inode will point to PTR_ERR(...) instead of NULL. This will result in null-ptr-deref when drm_fs_inode_free(dev->anon_inode) is called. drm_dev_init() drm_fs_inode_new() // fail, dev->anon_inode = PTR_ERR(...) drm_managed_release() drm_dev_init_release() drm_fs_inode_free() // access non-existent anon_inode Define a temp variable and assign it to dev->anon_inode if the temp variable is not PTR_ERR. Fixes: 2cbf7fc6718b ("drm: Use drmm_ for drm_dev_init cleanup") Reported-by: Hulk Robot Signed-off-by: Wang Hai --- drivers/gpu/drm/drm_drv.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 7a5097467ba5..b3a1636d1b98 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -581,6 +581,7 @@ static int drm_dev_init(struct drm_device *dev, const struct drm_driver *driver, struct device *parent) { + struct inode *inode; int ret; if (!drm_core_init_complete) { @@ -617,13 +618,15 @@ static int drm_dev_init(struct drm_device *dev, if (ret) return ret; - dev->anon_inode = drm_fs_inode_new(); - if (IS_ERR(dev->anon_inode)) { - ret = PTR_ERR(dev->anon_inode); + inode = drm_fs_inode_new(); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret); goto err; } + dev->anon_inode = inode; + if (drm_core_check_feature(dev, DRIVER_RENDER)) { ret = drm_minor_alloc(dev, DRM_MINOR_RENDER); if (ret)