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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 E89ABC43387 for ; Sun, 23 Dec 2018 00:55:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B84BD218F0 for ; Sun, 23 Dec 2018 00:55:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lekensteyn.nl header.i=@lekensteyn.nl header.b="Zrdy/8Yl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404343AbeLWAzR (ORCPT ); Sat, 22 Dec 2018 19:55:17 -0500 Received: from lekensteyn.nl ([178.21.112.251]:45979 "EHLO lekensteyn.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387711AbeLWAzQ (ORCPT ); Sat, 22 Dec 2018 19:55:16 -0500 X-Greylist: delayed 705 seconds by postgrey-1.27 at vger.kernel.org; Sat, 22 Dec 2018 19:55:14 EST DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lekensteyn.nl; s=s2048-2015-q1; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=5uUnM+MaNN9iLp3gnOrWEqvYAk+XSVGQm6uYqpP+lpE=; b=Zrdy/8YlHSjSuNkk0XYZjcNY643JH9lYM5YIPhMzX2LOycdjcZRsi4BCZrKuKX/awvv5w+o5OV565zS6QhcJLSehwUP13TCt3NUMQ4wBApcKh3YOA9IKbbTDFx5BEomiZZCMAbaJtSOlZjNz4QbcxdUHNbq5BeLwl6HA7rP8hyYpjWJtGLxht+q7JFVSu1Wq+TpGLBFCcioKPduqktWCcE3I6kM6wrMVQQtybIqf5LZp2yrFQpNUB4gCEiSq1ALGg7Qj8z2AaSBd758kyPcnUMkjjvfgNG85gMRPfpP6cnxYeMwKKzOY2r3RihovHiPvTBDxtg6zG0F0fhhJaHrk1g==; Received: by lekensteyn.nl with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1gas2u-0004I9-V9; Sun, 23 Dec 2018 01:55:09 +0100 From: Peter Wu To: dri-devel@lists.freedesktop.org Cc: Linus Torvalds , rong.a.chen@intel.com, kraxel@redhat.com, Daniel Vetter , Linux List Kernel Mailing , lkp@01.org, =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= Subject: [PATCH] drm/fb-helper: fix leaks in error path of drm_fb_helper_fbdev_setup Date: Sun, 23 Dec 2018 01:55:07 +0100 Message-Id: <20181223005507.28328-1-peter@lekensteyn.nl> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20181223004315.GA11455@al> References: <20181223004315.GA11455@al> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After drm_fb_helper_fbdev_setup calls drm_fb_helper_init, "dev->fb_helper" will be initialized (and thus drm_fb_helper_fini will have some effect). After that, drm_fb_helper_initial_config is called which may call the "fb_probe" driver callback. This driver callback may call drm_fb_helper_defio_init (as is done by drm_fb_helper_generic_probe) or set a framebuffer (as is done by bochs) as documented. These are normally cleaned up on exit by drm_fb_helper_fbdev_teardown which also calls drm_fb_helper_fini. If an error occurs after "fb_probe", but before setup is complete, then calling just drm_fb_helper_fini will leak resources. This was triggered by df2052cc922 ("bochs: convert to drm_fb_helper_fbdev_setup/teardown"): [ 50.008030] bochsdrmfb: enable CONFIG_FB_LITTLE_ENDIAN to support this framebuffer [ 50.009436] bochs-drm 0000:00:02.0: [drm:drm_fb_helper_fbdev_setup] *ERROR* fbdev: Failed to set configuration (ret=-38) [ 50.011456] [drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on minor 2 [ 50.013604] WARNING: CPU: 1 PID: 1 at drivers/gpu/drm/drm_mode_config.c:477 drm_mode_config_cleanup+0x280/0x2a0 [ 50.016175] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G T 4.20.0-rc7 #1 [ 50.017732] EIP: drm_mode_config_cleanup+0x280/0x2a0 ... [ 50.023155] Call Trace: [ 50.023155] ? bochs_kms_fini+0x1e/0x30 [ 50.023155] ? bochs_unload+0x18/0x40 This can be reproduced with QEMU and CONFIG_FB_LITTLE_ENDIAN=n. Link: https://lkml.kernel.org/r/20181221083226.GI23332@shao2-debian Link: https://lkml.kernel.org/r/20181223004315.GA11455@al Fixes: 8741216396b2 ("drm/fb-helper: Add drm_fb_helper_fbdev_setup/teardown()") Reported-by: kernel test robot Cc: Noralf Trønnes Signed-off-by: Peter Wu --- drivers/gpu/drm/drm_fb_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 9d64f874f965..432e0f3b9267 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2860,7 +2860,7 @@ int drm_fb_helper_fbdev_setup(struct drm_device *dev, return 0; err_drm_fb_helper_fini: - drm_fb_helper_fini(fb_helper); + drm_fb_helper_fbdev_teardown(dev); return ret; } -- 2.20.0