From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8AE91185955 for ; Wed, 13 Nov 2024 08:39:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731487169; cv=none; b=BjReHUDb9ywgowMXnzvlmiyI4wYg7h9+yz+lUkOWa7z8SfqrLW7qE2ETIe1V3JOt1thwoynfTDYGaJzLaYia4pwvatGyhTI+/qE8v94P0zqYKlbHDUSH2Fevg++OP8px8qj1PDcuaef8RgUKliiyLubgtibqRU6uqeBDzcHfUw4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731487169; c=relaxed/simple; bh=Jqov2zQMAO9Sr2bnnkqFB1XWwqVX8VIxrrgU5n0LkAI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=unLNNCCCSA3LNXJ9b/yQg6D5DnQws52laeNFFDiMU7RaWPVj0kg7hKHoCZTspSR60iK4qCMdJLBG45y38GfZZaNqyREMgmVZAzm6ZLtR/CcNh5iV4A30YuxPj3Ktkhgn9rPonoDjnqfJHRE97qjq2iP2zH2gx2mFl5KYNnmXFXw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=g8A+GEkI; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="g8A+GEkI" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-20e576dbc42so69622715ad.0 for ; Wed, 13 Nov 2024 00:39:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1731487166; x=1732091966; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=rCh54mJ7akDtjRQEtrxBL2HcuujeMrTCRb2aEAuUOGg=; b=g8A+GEkI0MOQnbpM3EYx90UfKmULdyjfSkA/MmyDnhlE7rg+yuVuy5CqxaacCoAX2R LY/9Ny8VRUyhVuo04ADJ4NXlG+TM0xfrrkIqkLNmAshMmUBein6BT+z0tPN9TgqFMwd9 V9LqsvdW3LPja0bkUjKOAGn5gyJzqhd2Bc1DQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731487166; x=1732091966; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=rCh54mJ7akDtjRQEtrxBL2HcuujeMrTCRb2aEAuUOGg=; b=ZiLKd3hu3FILUngbnDHM3mAGHM3uchWxiGmWRNsBuqflX3XbH7gAspPzzM/c0gmjRj qfV1ETAXvEG/gD/lr5hB8c2A5Vr7i3/UD0pQhnRqoiDukCQZ+ceV7+qOxP6W8TFqfva/ 5lCOkiCCY80oN7qIX2p8f5GTUox81t5xXuS1Z5kTtjEN81z4BWuo2mX5ZLr0cSwrk6L5 7ziTrTNSM3ROmtBJSp7gXqs3RQ6eZJD6gcPjI+dYhuNOg43HUbKxG8SgUiN2l571Nc02 Bekpx6iOnkaqsxrfOdKQepXDxpr5g2715omcNhY9SoygPWp4Qcz/FEk0Bxbxq5pA/E4F 0GkQ== X-Forwarded-Encrypted: i=1; AJvYcCWbyCxS3OjseXoMCTvS44QbXhe0mAur+qZBoWVJWuJhrFf6fdW66WgmdUxH/ZzuyibmD7ClA8cn+RGEjXA=@vger.kernel.org X-Gm-Message-State: AOJu0Yy/dSguuIw4QqAiVNaQBUWH8oC/3yGhYHjAMIeI9iNMe3V3H76C cCyGivnHicknzSK+AqUj67SNSUZCqAl+LcfvzcRXco4p3C87kyEIgE+aTXssQQ== X-Google-Smtp-Source: AGHT+IGofwp7EUeDXY7jIEE+cvpp5/5zwkzHjXcN1QEH+3rUbiVmbD0XfKX42r84LsLTqCr/8CqElQ== X-Received: by 2002:a17:903:2ac6:b0:20c:e169:eb75 with SMTP id d9443c01a7336-211b65d93c4mr20172145ad.2.1731487165765; Wed, 13 Nov 2024 00:39:25 -0800 (PST) Received: from google.com ([2401:fa00:8f:203:50c:65db:bb29:3cca]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21177e41890sm106064175ad.147.2024.11.13.00.39.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Nov 2024 00:39:25 -0800 (PST) Date: Wed, 13 Nov 2024 17:39:20 +0900 From: Sergey Senozhatsky To: Sergey Senozhatsky Cc: David Airlie , Simona Vetter , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH] drm: i915: do not NULL deref hdmi attached_connector Message-ID: <20241113083920.GH1458936@google.com> References: <20241031105145.2140590-1-senozhatsky@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241031105145.2140590-1-senozhatsky@chromium.org> On (24/10/31 19:51), Sergey Senozhatsky wrote: > intel_ddi_init() may skip connector initialization, for instance, > both intel_ddi_init_dp_connector() and intel_ddi_init_hdmi_connector() > are optional. This leads to situation that ->attached_connector may > be NULL for some connectors. For instance, on my setup 'DDI A/PHY A' > and 'DDI TC1/PHY TC1' are not initialized. > > However, functions like intel_dp_dual_mode_set_tmds_output() and > friends don't take this into consideration. This leads to NULL > ptr-derefs: > > KASAN: null-ptr-deref in range [0x0000000000000848-0x000000000000084f] > RIP: 0010:intel_hdmi_encoder_shutdown+0x105/0x230 > Call Trace: > > i915_driver_shutdown+0x2d8/0x490 > pci_device_shutdown+0x83/0x150 > device_shutdown+0x4ad/0x660 > __se_sys_reboot+0x29c/0x4d0 > do_syscall_64+0x60/0x90 > > Add a new helper to avoid NULL ->attached_connector derefs and > switch some intel_hdmi function to it. I'm not sure if we need > to switch all or just intel_dp_dual_mode_set_tmds_output() (I > have only seen this one doing NULL derefs so far). Folks, any more comments / opinions on this? What should be the way forward?