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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 2EF30C4708F for ; Mon, 31 May 2021 14:06:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 164C96135C for ; Mon, 31 May 2021 14:06:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233339AbhEaOIb (ORCPT ); Mon, 31 May 2021 10:08:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:49502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231863AbhEaNnA (ORCPT ); Mon, 31 May 2021 09:43:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA4CE61483; Mon, 31 May 2021 13:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622467721; bh=/AR6sw5pzaS0ed642hqWFyYDQ9w5U8GATj9I4hP0v1I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vZ15utYCJcgcv4W9y3AeRK95nYN1q06+5d7j0wRgqPANSu9fHI6El57whIUQ0MJ2v EfHj/y2sSqAcJMxywcPoIJumZFYqtLacUrgATxeJO4EOsSAengWrSM2tvfFcvVivgT wdygLm6pMB5hWQ30iaQYk1Xsu6tEMteRXfMOqja0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Agner , Neil Armstrong , Martin Blumenstingl Subject: [PATCH 4.14 38/79] drm/meson: fix shutdown crash when component not probed Date: Mon, 31 May 2021 15:14:23 +0200 Message-Id: <20210531130637.235108218@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130636.002722319@linuxfoundation.org> References: <20210531130636.002722319@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: linux-kernel@vger.kernel.org From: Neil Armstrong commit 7cfc4ea78fc103ea51ecbacd9236abb5b1c490d2 upstream. When main component is not probed, by example when the dw-hdmi module is not loaded yet or in probe defer, the following crash appears on shutdown: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038 ... pc : meson_drv_shutdown+0x24/0x50 lr : platform_drv_shutdown+0x20/0x30 ... Call trace: meson_drv_shutdown+0x24/0x50 platform_drv_shutdown+0x20/0x30 device_shutdown+0x158/0x360 kernel_restart_prepare+0x38/0x48 kernel_restart+0x18/0x68 __do_sys_reboot+0x224/0x250 __arm64_sys_reboot+0x24/0x30 ... Simply check if the priv struct has been allocated before using it. Fixes: fa0c16caf3d7 ("drm: meson_drv add shutdown function") Reported-by: Stefan Agner Signed-off-by: Neil Armstrong Tested-by: Martin Blumenstingl Reviewed-by: Martin Blumenstingl Link: https://patchwork.freedesktop.org/patch/msgid/20210430082744.3638743-1-narmstrong@baylibre.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/meson/meson_drv.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/meson/meson_drv.c +++ b/drivers/gpu/drm/meson/meson_drv.c @@ -364,11 +364,12 @@ static int meson_probe_remote(struct pla static void meson_drv_shutdown(struct platform_device *pdev) { struct meson_drm *priv = dev_get_drvdata(&pdev->dev); - struct drm_device *drm = priv->drm; - DRM_DEBUG_DRIVER("\n"); - drm_kms_helper_poll_fini(drm); - drm_atomic_helper_shutdown(drm); + if (!priv) + return; + + drm_kms_helper_poll_fini(priv->drm); + drm_atomic_helper_shutdown(priv->drm); } static int meson_drv_probe(struct platform_device *pdev)