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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 ADB02C04AB6 for ; Sat, 1 Jun 2019 02:43:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7586D26FD5 for ; Sat, 1 Jun 2019 02:43:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="kzjqUEIT"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="FaulWKHr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726708AbfFACnh (ORCPT ); Fri, 31 May 2019 22:43:37 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39046 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726634AbfFACnh (ORCPT ); Fri, 31 May 2019 22:43:37 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id AB47860AD1; Sat, 1 Jun 2019 02:43:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1559357016; bh=EIGdHRTGMSH8BrR4fNTW/L7YHCj/dHmkgWPz/8baTkk=; h=From:To:Cc:Subject:Date:From; b=kzjqUEITrbZXR8nDM/ieBr3arNCD85iak0qOLuY92dXcPaNvKxX+Erwn5ygm+JQ7n neSiKTiSVcdphc/E3JsaM4mbLcU+Bv/Mi90VrG5Jz+xGVuRrZlF+PQN1J2C5qILLEy hU2+eNlNXaIYyLux0nz5I+X0n5HUylmh4ErqFrA4= Received: from abhinavk-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: abhinavk@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 8CFBB60312; Sat, 1 Jun 2019 02:43:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1559357015; bh=EIGdHRTGMSH8BrR4fNTW/L7YHCj/dHmkgWPz/8baTkk=; h=From:To:Cc:Subject:Date:From; b=FaulWKHrxQedjqxTPLe7lPVM3Ogjdr7ayPTSHSYQ9X/dQs5BadNcsH14fFIEFH2E1 P+h8Q4MiYuATcH54SupiS9EeHuQlCYuiahOVeqh9EkWryU7B+w+t+Ac8Ol5CwGb+et CIV57FL+ART+JjJa95Jbtpw3gR7uyXSKfOJ4UgKs= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8CFBB60312 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=abhinavk@codeaurora.org From: Abhinav Kumar To: dri-devel@lists.freedesktop.org Cc: Abhinav Kumar , linux-arm-msm@vger.kernel.org, robdclark@gmail.com, jsanka@codeaurora.org, seanpaul@chromium.org, nganji@codeaurora.org, chandanu@codeaurora.org, hoegsberg@google.com Subject: [PATCH v2] drm/msm/dsi: add protection against NULL dsi device Date: Fri, 31 May 2019 19:43:27 -0700 Message-Id: <1559357007-21004-1-git-send-email-abhinavk@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org When panel probe happens after DSI probe, the DSI probe is deferred as per current design. In the probe defer path dsi device is destroyed. This NULL dsi device could be deferenced by the panel probe in the mipi_dsi_attach path. Check for NULL dsi device before accessing it. Changes in v2: - Add more comments on how this NULL pointer situation will be hit Reported-by: Jeffrey Hugo Tested-by: Jeffrey Hugo Signed-off-by: Abhinav Kumar --- drivers/gpu/drm/msm/dsi/dsi_manager.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 80aa634..8fcb13f 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -769,7 +769,7 @@ bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len) void msm_dsi_manager_attach_dsi_device(int id, u32 device_flags) { struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id); - struct drm_device *dev = msm_dsi->dev; + struct drm_device *dev; struct msm_drm_private *priv; struct msm_kms *kms; struct drm_encoder *encoder; @@ -781,7 +781,17 @@ void msm_dsi_manager_attach_dsi_device(int id, u32 device_flags) * (generally the case when we're connected to a drm_panel of the type * mipi_dsi_device), this would be NULL. In such cases, try to set the * encoder mode in the DSI connector's detect() op. + * + * msm_dsi pointer is assigned to a valid dsi device only when + * msm_dsi_manager_register() succeeds. When panel hasnt probed yet + * dsi_mgr_setup_components() could potentially return -EDEFER and + * assign the msm_dsi->dev to NULL. When the panel now probes and calls + * mipi_dsi_attach(), this will call msm_dsi_manager_attach_dsi_device() + * which will result in a NULL pointer dereference */ + + dev = msm_dsi ? msm_dsi->dev : NULL; + if (!dev) return; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project