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 73B58C4332F for ; Mon, 24 Jan 2022 20:38:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386122AbiAXUfL (ORCPT ); Mon, 24 Jan 2022 15:35:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1384767AbiAXUad (ORCPT ); Mon, 24 Jan 2022 15:30:33 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 542D0C08B4D9; Mon, 24 Jan 2022 11:42:54 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D2BE36135E; Mon, 24 Jan 2022 19:42:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4073C340E5; Mon, 24 Jan 2022 19:42:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643053373; bh=q06pqYo6uEXuUELP82UDgfcUYfD4+EybH2C9KbzgQ4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GcacAnTQH76Ha4NCVjylc/LJ/dIeHx73uBkXPtSUGhUvm9N+GcklEHii2GXzY18L8 Y7YTNYIcarxf2/KtWea6e4zCriTEQ9HJrg8iDNxohR1eQ8myCaSHA3jAwbXIq852Y9 q5Mcxr6J4fUCh6SHwZPL6o02BzyV0F1vt9+jVTQg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Wang Hai , Sam Ravnborg , Sasha Levin Subject: [PATCH 5.10 044/563] drm: fix null-ptr-deref in drm_dev_init_release() Date: Mon, 24 Jan 2022 19:36:49 +0100 Message-Id: <20220124184025.937609654@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184024.407936072@linuxfoundation.org> References: <20220124184024.407936072@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wang Hai [ Upstream commit acf20ed020ffa4d6cc8347e8d356509b95df3cbe ] 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 Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20211013114139.4042207-1-wanghai38@huawei.com Signed-off-by: Sasha Levin --- 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 cd162d406078a..006e3b896caea 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -577,6 +577,7 @@ static int drm_dev_init(struct drm_device *dev, struct drm_driver *driver, struct device *parent) { + struct inode *inode; int ret; if (!drm_core_init_complete) { @@ -613,13 +614,15 @@ 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) -- 2.34.1