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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 8AF7EC35640 for ; Fri, 21 Feb 2020 07:47:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 598B624650 for ; Fri, 21 Feb 2020 07:47:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582271275; bh=xzcDHUr0AgOeeRhMZggU0VLWyxXQOHzz4fX3m50JerA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K0pLzut78bpeaWTy7KutamI9uXJtgiDIUj8n+j98mQEolqhE4pty2t3asZ2bUlSGN gw/xyGSYzj13R/+1OHg3b2d/p6Fyapa3CbA3GDK+GzZWgnwbGWQ+tSrKs+qSdlhHe+ cIBVNHfx4P/beurwM8hGBTBE2DRGCYoN6P/eiQbs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728572AbgBUHry (ORCPT ); Fri, 21 Feb 2020 02:47:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:43788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728983AbgBUHrt (ORCPT ); Fri, 21 Feb 2020 02:47:49 -0500 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 B173424650; Fri, 21 Feb 2020 07:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582271269; bh=xzcDHUr0AgOeeRhMZggU0VLWyxXQOHzz4fX3m50JerA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pBdfrdubnQYnD2B9YXlz2GoSk99kydFezGxpl3sj1lQ0ov0DWCNaYhqZ2TJpjIE8l TuuzEGVSRV3Z2Dh+Vb4a7PFK/kukCM+vosb2szsDCsUcYs6nnbnYDLe+Wci0sDGHcA pduUEoMxMdMcLIPK6G3AXjNfkp2UXSQvvWmC96S4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Douglas Anderson , Matthias Kaehlcke , Stephen Boyd , Sasha Levin Subject: [PATCH 5.5 101/399] clk: qcom: rcg2: Dont crash if our parent cant be found; return an error Date: Fri, 21 Feb 2020 08:37:06 +0100 Message-Id: <20200221072412.231451921@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072402.315346745@linuxfoundation.org> References: <20200221072402.315346745@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 From: Douglas Anderson [ Upstream commit 908b050114d8fefdddc57ec9fbc213c3690e7f5f ] When I got my clock parenting slightly wrong I ended up with a crash that looked like this: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ... pc : clk_hw_get_rate+0x14/0x44 ... Call trace: clk_hw_get_rate+0x14/0x44 _freq_tbl_determine_rate+0x94/0xfc clk_rcg2_determine_rate+0x2c/0x38 clk_core_determine_round_nolock+0x4c/0x88 clk_core_round_rate_nolock+0x6c/0xa8 clk_core_round_rate_nolock+0x9c/0xa8 clk_core_set_rate_nolock+0x70/0x180 clk_set_rate+0x3c/0x6c of_clk_set_defaults+0x254/0x360 platform_drv_probe+0x28/0xb0 really_probe+0x120/0x2dc driver_probe_device+0x64/0xfc device_driver_attach+0x4c/0x6c __driver_attach+0xac/0xc0 bus_for_each_dev+0x84/0xcc driver_attach+0x2c/0x38 bus_add_driver+0xfc/0x1d0 driver_register+0x64/0xf8 __platform_driver_register+0x4c/0x58 msm_drm_register+0x5c/0x60 ... It turned out that clk_hw_get_parent_by_index() was returning NULL and we weren't checking. Let's check it so that we don't crash. Fixes: ac269395cdd8 ("clk: qcom: Convert to clk_hw based provider APIs") Signed-off-by: Douglas Anderson Reviewed-by: Matthias Kaehlcke Link: https://lkml.kernel.org/r/20200203103049.v4.1.I7487325fe8e701a68a07d3be8a6a4b571eca9cfa@changeid Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin --- drivers/clk/qcom/clk-rcg2.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 5e0f7d8f168dd..cecdb07ce13ba 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -217,6 +217,9 @@ static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f, clk_flags = clk_hw_get_flags(hw); p = clk_hw_get_parent_by_index(hw, index); + if (!p) + return -EINVAL; + if (clk_flags & CLK_SET_RATE_PARENT) { rate = f->freq; if (f->pre_div) { -- 2.20.1