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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 54F03C3B19F for ; Fri, 14 Feb 2020 16:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E2B824680 for ; Fri, 14 Feb 2020 16:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581698612; bh=Omc6XSnNs5KMFz1tBz8lSNoR8tkXrcQQyKZa4berMYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Zjg3RKELbfMSu8xVqtcFVtr+rfVc0UN1K23E0m0GNcRIVt959ImeVeO9K/j4TJ9B7 7aR0rSbZuQTXte70xyiSSkMJWyIOtsJbzGn0vxZfrdMoTwtGMM8um3frnwoTcaU6br Kkb0nSGjGNIXXiWBbp0MK6RLUFX4jBrWr4tIk5Vg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405135AbgBNQWD (ORCPT ); Fri, 14 Feb 2020 11:22:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:57038 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405061AbgBNQWD (ORCPT ); Fri, 14 Feb 2020 11:22:03 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4911B246D8; Fri, 14 Feb 2020 16:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581697322; bh=Omc6XSnNs5KMFz1tBz8lSNoR8tkXrcQQyKZa4berMYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cjbg+4uXM88/mvL71ebO3gFnAJWGvFvVzU4WQgOI5A010jBEAO+Se16H+B18TiYRi NLIJGP+9kQYRX1XjLXzxHCjB9838gMytbrcH5epRxXyhJFQUYS2o483PuWi5mECPHM ZSJIEkJmq7TGOxuOfis5Eo7F8SeS9sAhRjNqwJNw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Douglas Anderson , Matthias Kaehlcke , Stephen Boyd , Sasha Levin , linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 031/141] clk: qcom: rcg2: Don't crash if our parent can't be found; return an error Date: Fri, 14 Feb 2020 11:19:31 -0500 Message-Id: <20200214162122.19794-31-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214162122.19794-1-sashal@kernel.org> References: <20200214162122.19794-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 0ae1b0a66eb55..d8601b138dc1e 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -194,6 +194,9 @@ static int _freq_tbl_determine_rate(struct clk_hw *hw, 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) { if (f->pre_div) { if (!rate) -- 2.20.1