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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 CFE97C04AB1 for ; Thu, 9 May 2019 19:00:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2EEF2177B for ; Thu, 9 May 2019 19:00:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557428413; bh=ejtJlRKggDYSrnvS5XNrV6OwQHBXLxSQjZ7wIfmVLJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pT9jyP142p8gi7FIiIbHmniFm4Q4d3Ux+WRMM4szvnQJm/dvoelYmb4uGuIhhBpXi nxHewSu9fVAbZNcHytYbpezWCLUKvq2RXEWhJMsc3tSrjsU+N3UzUtEzrz6wVjArnT Vjp5ilzmA7C6VbpDkCNKLQdqwyeG6kntDscxn3iA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728955AbfEITAM (ORCPT ); Thu, 9 May 2019 15:00:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:45714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727147AbfEISvu (ORCPT ); Thu, 9 May 2019 14:51:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 857F7217F5; Thu, 9 May 2019 18:51:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557427910; bh=ejtJlRKggDYSrnvS5XNrV6OwQHBXLxSQjZ7wIfmVLJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z1ioYN+7WxP6hj/BEWCGAkdN2/6xUc6XCUKXqN0rz0ju6mqVH/jJJFlBIseo+mE78 V3MCTX/MPKVEPKxsmtDt/a35PcI4BrxXbwBWUK5AjI7bwlgfWubJj0DpkAwPRZCrAS t/PrB3TnilZjJA5fyOIPUoP4A/CJalTUlfNUQC1I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ondrej Jirman , Maxime Ripard , Sasha Levin Subject: [PATCH 5.0 49/95] drm/sun4i: tcon top: Fix NULL/invalid pointer dereference in sun8i_tcon_top_un/bind Date: Thu, 9 May 2019 20:42:06 +0200 Message-Id: <20190509181312.902008471@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190509181309.180685671@linuxfoundation.org> References: <20190509181309.180685671@linuxfoundation.org> User-Agent: quilt/0.66 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 [ Upstream commit 1a07a94b47b1f528f39c3e6187b5eaf02efe44ea ] There are two problems here: 1. Not all clk_data->hws[] need to be initialized, depending on various configured quirks. This leads to NULL ptr deref in clk_hw_unregister_gate() in sun8i_tcon_top_unbind() 2. If there is error when registering the clk_data->hws[], err_unregister_gates error path will try to unregister IS_ERR()=true (invalid) pointer. For problem (1) I have this stack trace: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Call trace: clk_hw_unregister+0x8/0x18 clk_hw_unregister_gate+0x14/0x28 sun8i_tcon_top_unbind+0x2c/0x60 component_unbind.isra.4+0x2c/0x50 component_bind_all+0x1d4/0x230 sun4i_drv_bind+0xc4/0x1a0 try_to_bring_up_master+0x164/0x1c0 __component_add+0xa0/0x168 component_add+0x10/0x18 sun8i_dw_hdmi_probe+0x18/0x20 platform_drv_probe+0x3c/0x70 really_probe+0xcc/0x278 driver_probe_device+0x34/0xa8 Problem (2) was identified by head scratching. Signed-off-by: Ondrej Jirman Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20190405233048.3823-1-megous@megous.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c index fc36e0c10a374..b1e7c76e9c172 100644 --- a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c @@ -227,7 +227,7 @@ static int sun8i_tcon_top_bind(struct device *dev, struct device *master, err_unregister_gates: for (i = 0; i < CLK_NUM; i++) - if (clk_data->hws[i]) + if (!IS_ERR_OR_NULL(clk_data->hws[i])) clk_hw_unregister_gate(clk_data->hws[i]); clk_disable_unprepare(tcon_top->bus); err_assert_reset: @@ -245,7 +245,8 @@ static void sun8i_tcon_top_unbind(struct device *dev, struct device *master, of_clk_del_provider(dev->of_node); for (i = 0; i < CLK_NUM; i++) - clk_hw_unregister_gate(clk_data->hws[i]); + if (clk_data->hws[i]) + clk_hw_unregister_gate(clk_data->hws[i]); clk_disable_unprepare(tcon_top->bus); reset_control_assert(tcon_top->rst); -- 2.20.1