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 297F8C433F5 for ; Tue, 22 Mar 2022 14:28:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234381AbiCVO3q (ORCPT ); Tue, 22 Mar 2022 10:29:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237676AbiCVO3b (ORCPT ); Tue, 22 Mar 2022 10:29:31 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 550C9433AF for ; Tue, 22 Mar 2022 07:27:36 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id 123-20020a1c1981000000b0038b3616a71aso1941091wmz.4 for ; Tue, 22 Mar 2022 07:27:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=aFJ8fEE2GmOZRq2LQko1sVV66aL7LKjJL0NKXhRxHqI=; b=V5Fveq5WdZ2O1E/UHe/Kd/2Tq2XKcYmKLrvMgQL0ZFn3w2rYOsfKLTxdYURrm/8Avw sSpJwrhVxtG4ih+/xD4Wp6wFgRCVFiTJf8f0hRjgQwRyr8ayboOqmEZ++brrpQ09jSwq otAb7ac5DrVEvEv7se0+mm3/EiGGLLRX0kyGs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=aFJ8fEE2GmOZRq2LQko1sVV66aL7LKjJL0NKXhRxHqI=; b=OzrDJtHZ3BuIGy/2TVCBR6Hv7D+ySRvE1p9oqZOOPYGsN487gwtVNvKELEUmsd+RxJ 99aYYXwEkwSZVkIQWpyUPfvTRYIuB6XFfRC6bZcZTdcFqoPor2/tQJ1pSphoaeTyT9Ca Nwb8ZAT0Iy6vY9YVCaqrFHFd9JI1bvGoe2Am6DlW5iuQqcCGkUQz8q5ssDUcmsst5BB5 BVev+53wRpFj7HpcOTw7ZyVTfBoGNjo73U1qoV7mPdPvo+Y6S6IY8wtBfQMtCD0T2bJq xtJD3sBlt8cPmDTRhw8Gl0/fuQv0Tx4bMRm9aD2MSikebrqkzSFsMBuAdR/hMCufhbgt DDgA== X-Gm-Message-State: AOAM530+kUTJQQ5V0ReEs+YAm1bMmTCWX+4wDF7HVBgHFfULIOR86m0R pRpoOF83+WmXb0FjPzJgrj82Jw== X-Google-Smtp-Source: ABdhPJxOqZteDgpdZsZu0oPCEXdNAPTFOjbUarDx25uP8lDbSGAd7h8aMt73l8sJSR0+303XjDYMnA== X-Received: by 2002:a05:600c:3ca8:b0:38c:6dc6:6de0 with SMTP id bg40-20020a05600c3ca800b0038c6dc66de0mr4092167wmb.159.1647959254730; Tue, 22 Mar 2022 07:27:34 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id l19-20020a05600c4f1300b0038cb924c3d7sm1461155wmq.45.2022.03.22.07.27.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Mar 2022 07:27:34 -0700 (PDT) Date: Tue, 22 Mar 2022 15:27:32 +0100 From: Daniel Vetter To: Zheyu Ma Cc: maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@linux.ie, dri-devel@lists.freedesktop.org, Linux Kernel Mailing List , Daniel Vetter Subject: Re: [PATCH] drm: drm_bufs: Error out if 'dev->agp' is a null pointer Message-ID: Mail-Followup-To: Zheyu Ma , maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@linux.ie, dri-devel@lists.freedesktop.org, Linux Kernel Mailing List References: <1646983382-30036-1-git-send-email-zheyuma97@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 5.10.0-8-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 21, 2022 at 09:02:47PM +0800, Zheyu Ma wrote: > On Thu, Mar 17, 2022 at 6:49 PM Daniel Vetter wrote: > > > > On Fri, Mar 11, 2022 at 07:23:02AM +0000, Zheyu Ma wrote: > > > The user program can control the 'drm_buf_desc::flags' via ioctl system > > > call and enter the function drm_legacy_addbufs_agp(). If the driver > > > doesn't initialize the agp resources, the driver will cause a null > > > pointer dereference. > > > > > > The following log reveals it: > > > general protection fault, probably for non-canonical address > > > 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI > > > KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] > > > Call Trace: > > > > > > drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 > > > drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 > > > vfs_ioctl fs/ioctl.c:51 [inline] > > > __do_sys_ioctl fs/ioctl.c:874 [inline] > > > __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 > > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > > do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 > > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > > > > Fix this bug by adding a check. > > > > > > Signed-off-by: Zheyu Ma > > > > You can only hit this if you enabled a DRIVER_LEGACY drm driver, which > > opens you up to tons of other CVEs and issues. What's your .config? > > Yes, I enable the DRM_LEGACY option in the config. > I think you mean this is not a normal configuration file? Do you have > a recommended configuration option for when I want to test the GPU > driver? Yeah DRM_LEGACY gives you all kinds of horrible and known-broken interfaces. Don't enable that :-) You have a bunch of other drivers enable which require DRM_LEGACY, so those will disable too. Anything else I think would be an upstream bug and we'd need to adjust Kconfig (or fix the code). Cheers, Daniel > > Actually, I use the following configs related to GPU: > > CONFIG_AGP=y > CONFIG_AGP_AMD64=y > CONFIG_AGP_INTEL=y > CONFIG_AGP_SIS=y > CONFIG_AGP_VIA=y > CONFIG_INTEL_GTT=y > CONFIG_VGA_ARB=y > CONFIG_VGA_ARB_MAX_GPUS=16 > CONFIG_DRM=y > CONFIG_DRM_MIPI_DSI=y > CONFIG_DRM_KMS_HELPER=y > CONFIG_DRM_DEBUG_MODESET_LOCK=y > CONFIG_DRM_FBDEV_EMULATION=y > CONFIG_DRM_FBDEV_OVERALLOC=100 > CONFIG_DRM_TTM=y > CONFIG_DRM_VRAM_HELPER=y > CONFIG_DRM_TTM_HELPER=y > CONFIG_DRM_GEM_SHMEM_HELPER=y > CONFIG_DRM_SCHED=y > CONFIG_DRM_RADEON=y > CONFIG_DRM_AMDGPU=y > CONFIG_DRM_AMD_DC=y > CONFIG_DRM_AMD_DC_DCN=y > CONFIG_DRM_I915=y > CONFIG_DRM_I915_FORCE_PROBE="" > CONFIG_DRM_I915_CAPTURE_ERROR=y > CONFIG_DRM_I915_COMPRESS_ERROR=y > CONFIG_DRM_I915_USERPTR=y > CONFIG_DRM_I915_REQUEST_TIMEOUT=20000 > CONFIG_DRM_I915_FENCE_TIMEOUT=10000 > CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND=250 > CONFIG_DRM_I915_HEARTBEAT_INTERVAL=2500 > CONFIG_DRM_I915_PREEMPT_TIMEOUT=640 > CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT=8000 > CONFIG_DRM_I915_STOP_TIMEOUT=100 > CONFIG_DRM_I915_TIMESLICE_DURATION=1 > CONFIG_DRM_VMWGFX=y > CONFIG_DRM_GMA500=y > CONFIG_DRM_UDL=y > CONFIG_DRM_AST=y > CONFIG_DRM_MGAG200=y > CONFIG_DRM_QXL=y > CONFIG_DRM_VIRTIO_GPU=y > CONFIG_DRM_PANEL=y > CONFIG_DRM_BRIDGE=y > CONFIG_DRM_PANEL_BRIDGE=y > CONFIG_DRM_BOCHS=y > CONFIG_DRM_CIRRUS_QEMU=y > CONFIG_DRM_GM12U320=y > CONFIG_DRM_VBOXVIDEO=y > CONFIG_DRM_GUD=y > CONFIG_DRM_HYPERV=y > CONFIG_DRM_LEGACY=y > CONFIG_DRM_TDFX=y > CONFIG_DRM_R128=y > CONFIG_DRM_MGA=y > CONFIG_DRM_SIS=y > CONFIG_DRM_VIA=y > CONFIG_DRM_SAVAGE=y > CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y > > Thanks, > Zheyu Ma -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch