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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 04832CD37B5 for ; Mon, 11 May 2026 09:04:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 487AC10E4FB; Mon, 11 May 2026 09:04:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="NTGQztaf"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id D395110E4FB for ; Mon, 11 May 2026 09:04:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1778490268; x=1810026268; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=1hHtE+qiixejcQON712uNfesppDbsdiUfLRUqiVc6aI=; b=NTGQztafJFJg6Xs9i9+pSkxX4k3aFYEGr/0yXk9/BBgBTBPenkKrjvdT G46ar7oIEVh1H3d2UmIBk8I58HJu7HkI/siehTfkWWAJdn83w496cJhb7 QfbxxoF6df45kfQs0sAgdAFJFirI3vKYyrSh8IyPSFxe03n8MHInrcGV8 ZoPcQCmy74/ik2Iw8gh0m8ISDF5pBKWFXTRosqIvbfux306HyDNz1tffd QjK+VDwCPfNY1JUZ6wS1Gu7u87xIfQWQHPbrs6IZxaj15ih9vhXT/+hUb ykLfQM1smcl61yqXtVOm5ZBMkglhuLj2TE3BY6UxQFh5IbCDjvXRknmgr g==; X-CSE-ConnectionGUID: XdqQGVYiSLW3yWpPuw7IpQ== X-CSE-MsgGUID: a8Vb1Pr4QmiMjLtf4diwpg== X-IronPort-AV: E=McAfee;i="6800,10657,11782"; a="89676599" X-IronPort-AV: E=Sophos;i="6.23,228,1770624000"; d="scan'208";a="89676599" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2026 02:04:27 -0700 X-CSE-ConnectionGUID: 1jP2xWNfQPCQ5XZKIGqUtg== X-CSE-MsgGUID: U9GJ5rlqTfOIW8tFirLliw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,228,1770624000"; d="scan'208";a="241372324" Received: from unknown (HELO [10.102.88.33]) ([10.102.88.33]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2026 02:04:23 -0700 Message-ID: <0097f608-dbac-482d-9851-ce306b0c7b78@linux.intel.com> Date: Mon, 11 May 2026 11:04:21 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] accel/ivpu: Reject PRIME export of userptr BOs To: =?UTF-8?Q?Christian_K=C3=B6nig?= , Ziyi Guo , maciej.falkowski@linux.intel.com, jacek.lawrynowicz@linux.intel.com Cc: ogabbay@kernel.org, sumit.semwal@linaro.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, Ziyi Guo References: <20260508162856.1131843-1-n7l8m4@u.northwestern.edu> <14b62cee-c46e-4fb9-91ab-aa09c0962834@amd.com> Content-Language: en-US From: Karol Wachowski Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <14b62cee-c46e-4fb9-91ab-aa09c0962834@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 5/11/2026 9:39 AM, Christian König wrote: > Hi Zivi, > > On 5/8/26 18:28, Ziyi Guo wrote: >> Userptr BOs wrap pinned user pages in a private dma-buf solely for >> internal use by the NPU driver. Allowing userspace to re-export such a >> BO via DRM_IOCTL_PRIME_HANDLE_TO_FD would expose those pages to other >> drivers through an interface that was never intended to be shared. >> >> Override the driver's prime_handle_to_fd callback to detect dma-bufs >> backed by ivpu_gem_userptr_dmabuf_ops and reject the export with >> -EINVAL. >> >> Signed-off-by: Ziyi Guo > Hi Christian > first of all thanks a lot for pointing that out! The patch which orginally added that somehow slipped through the cracks. > > Then @Karol and @Jacek, using DMA-buf like that is a pretty big NO-GO from the DMA-buf side! > > Using page which you don't own (especially file system backend ones) in a DMA-buf is absolutely *NOT* something you can do. > > I hope that it is not the case here, but if you also allow to mmap() them then you have create a massive security problem which can lead to random file system corruptions. This is not allowed, ivpu userpointer dma_buf_ops have no .mmap handler, this results in -EINVAL when invoked. Regards, Karol > > Regards, > Christian. > >> --- >> drivers/accel/ivpu/ivpu_drv.c | 1 + >> drivers/accel/ivpu/ivpu_gem.c | 28 +++++++++++++++++++++++++++ >> drivers/accel/ivpu/ivpu_gem.h | 3 +++ >> drivers/accel/ivpu/ivpu_gem_userptr.c | 5 +++++ >> 4 files changed, 37 insertions(+) >> >> diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c >> index 2801378e3e19..086d4c769b33 100644 >> --- a/drivers/accel/ivpu/ivpu_drv.c >> +++ b/drivers/accel/ivpu/ivpu_drv.c >> @@ -545,6 +545,7 @@ static const struct drm_driver driver = { >> >> .gem_create_object = ivpu_gem_create_object, >> .gem_prime_import = ivpu_gem_prime_import, >> + .prime_handle_to_fd = ivpu_gem_prime_handle_to_fd, >> >> .ioctls = ivpu_drm_ioctls, >> .num_ioctls = ARRAY_SIZE(ivpu_drm_ioctls), >> diff --git a/drivers/accel/ivpu/ivpu_gem.c b/drivers/accel/ivpu/ivpu_gem.c >> index 4f2005a8d496..82079f372b39 100644 >> --- a/drivers/accel/ivpu/ivpu_gem.c >> +++ b/drivers/accel/ivpu/ivpu_gem.c >> @@ -12,6 +12,7 @@ >> #include >> #include >> #include >> +#include >> #include >> >> #include "ivpu_drv.h" >> @@ -249,6 +250,33 @@ struct drm_gem_object *ivpu_gem_prime_import(struct drm_device *dev, >> return ERR_PTR(ret); >> } >> >> +int ivpu_gem_prime_handle_to_fd(struct drm_device *dev, struct drm_file *file_priv, >> + u32 handle, u32 flags, int *prime_fd) >> +{ >> + struct ivpu_device *vdev = to_ivpu_device(dev); >> + struct dma_buf *dmabuf; >> + int fd; >> + >> + dmabuf = drm_gem_prime_handle_to_dmabuf(dev, file_priv, handle, flags); >> + if (IS_ERR(dmabuf)) >> + return PTR_ERR(dmabuf); >> + >> + if (ivpu_gem_is_userptr_dma_buf(dmabuf)) { >> + ivpu_dbg(vdev, IOCTL, "Exporting userptr BO is not allowed\n"); >> + dma_buf_put(dmabuf); >> + return -EINVAL; >> + } >> + >> + fd = dma_buf_fd(dmabuf, flags); >> + if (fd < 0) { >> + dma_buf_put(dmabuf); >> + return fd; >> + } >> + >> + *prime_fd = fd; >> + return 0; >> +} >> + >> static struct ivpu_bo *ivpu_bo_alloc(struct ivpu_device *vdev, u64 size, u32 flags) >> { >> struct drm_gem_shmem_object *shmem; >> diff --git a/drivers/accel/ivpu/ivpu_gem.h b/drivers/accel/ivpu/ivpu_gem.h >> index 0c3350f22b55..bfd15ce02354 100644 >> --- a/drivers/accel/ivpu/ivpu_gem.h >> +++ b/drivers/accel/ivpu/ivpu_gem.h >> @@ -29,6 +29,9 @@ void ivpu_bo_unbind_all_bos_from_context(struct ivpu_device *vdev, struct ivpu_m >> >> struct drm_gem_object *ivpu_gem_create_object(struct drm_device *dev, size_t size); >> struct drm_gem_object *ivpu_gem_prime_import(struct drm_device *dev, struct dma_buf *dma_buf); >> +int ivpu_gem_prime_handle_to_fd(struct drm_device *dev, struct drm_file *file_priv, >> + u32 handle, u32 flags, int *prime_fd); >> +bool ivpu_gem_is_userptr_dma_buf(struct dma_buf *dma_buf); >> struct ivpu_bo *ivpu_bo_create(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, >> struct ivpu_addr_range *range, u64 size, u32 flags); >> struct ivpu_bo *ivpu_bo_create_runtime(struct ivpu_device *vdev, u64 addr, u64 size, u32 flags); >> diff --git a/drivers/accel/ivpu/ivpu_gem_userptr.c b/drivers/accel/ivpu/ivpu_gem_userptr.c >> index 7cbf3a4cdc73..45eabea5961e 100644 >> --- a/drivers/accel/ivpu/ivpu_gem_userptr.c >> +++ b/drivers/accel/ivpu/ivpu_gem_userptr.c >> @@ -61,6 +61,11 @@ static const struct dma_buf_ops ivpu_gem_userptr_dmabuf_ops = { >> .release = ivpu_gem_userptr_dmabuf_release, >> }; >> >> +bool ivpu_gem_is_userptr_dma_buf(struct dma_buf *dma_buf) >> +{ >> + return dma_buf->ops == &ivpu_gem_userptr_dmabuf_ops; >> +} >> + >> static struct dma_buf * >> ivpu_create_userptr_dmabuf(struct ivpu_device *vdev, void __user *user_ptr, >> size_t size, uint32_t flags) >> -- >> 2.34.1 >> >