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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56003C7EE26 for ; Mon, 8 May 2023 11:02:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235286AbjEHLCs (ORCPT ); Mon, 8 May 2023 07:02:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235528AbjEHLCe (ORCPT ); Mon, 8 May 2023 07:02:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A47C2BCC1 for ; Mon, 8 May 2023 04:01:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BA60162A3E for ; Mon, 8 May 2023 11:01:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4202C433EF; Mon, 8 May 2023 11:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683543677; bh=8nmbrug1N676rGjISLq76/epLCNfpaH/EUNoNZZcens=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BpWU36GEv0BdLSw5DYe4dMPehwPtP9P2DOwDQBRoNcEddKiiClBGh7chknsRZHdj7 q++zEJl+RvBrEWN6DRdyV6UWyopx1irDmW2WKCz2FuP95DyQdKTCzqmqnAAvQihHa0 oYuzPjUNgBZtqUkl7I1dAU/zvvR63rZLmpNSG9/4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chen-Yu Tsai , Guillaume Ranquet , AngeloGioacchino Del Regno , Matthias Brugger , Chun-Kuang Hu , Sasha Levin Subject: [PATCH 6.3 165/694] drm/mediatek: dp: Only trigger DRM HPD events if bridge is attached Date: Mon, 8 May 2023 11:40:00 +0200 Message-Id: <20230508094437.764629704@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chen-Yu Tsai [ Upstream commit 36b617f7e4ae663fcadd202ea061ca695ca75539 ] The MediaTek DisplayPort interface bridge driver starts its interrupts as soon as its probed. However when the interrupts trigger the bridge might not have been attached to a DRM device. As drm_helper_hpd_irq_event() does not check whether the passed in drm_device is valid or not, a NULL pointer passed in results in a kernel NULL pointer dereference in it. Check whether the bridge is attached and only trigger an HPD event if it is. Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") Signed-off-by: Chen-Yu Tsai Reviewed-by: Guillaume Ranquet Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Matthias Brugger Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20230202045734.2773503-1-wenst@chromium.org/ Signed-off-by: Chun-Kuang Hu Signed-off-by: Sasha Levin --- drivers/gpu/drm/mediatek/mtk_dp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index 1f94fcc144d3a..a82f53e1a1462 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -1823,7 +1823,8 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev) spin_unlock_irqrestore(&mtk_dp->irq_thread_lock, flags); if (status & MTK_DP_THREAD_CABLE_STATE_CHG) { - drm_helper_hpd_irq_event(mtk_dp->bridge.dev); + if (mtk_dp->bridge.dev) + drm_helper_hpd_irq_event(mtk_dp->bridge.dev); if (!mtk_dp->train_info.cable_plugged_in) { mtk_dp_disable_sdp_aui(mtk_dp); -- 2.39.2