From nobody Thu May 7 19:55:04 2026 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 67D73C433F5 for ; Thu, 19 May 2022 15:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240746AbiESPUV (ORCPT ); Thu, 19 May 2022 11:20:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230063AbiESPUO (ORCPT ); Thu, 19 May 2022 11:20:14 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D64F4C1EC8 for ; Thu, 19 May 2022 08:20:13 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9A48614BF; Thu, 19 May 2022 08:20:13 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.25.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 831E33F66F; Thu, 19 May 2022 08:20:11 -0700 (PDT) From: Steven Price To: Rob Herring , Tomeu Vizoso , Alyssa Rosenzweig , Boris Brezillon Cc: Steven Price , Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/panfrost: Job should reference MMU not file_priv Date: Thu, 19 May 2022 16:20:03 +0100 Message-Id: <20220519152003.81081-1-steven.price@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" For a while now it's been allowed for a MMU context to outlive it's corresponding panfrost_priv, however the job structure still references panfrost_priv to get hold of the MMU context. If panfrost_priv has been freed this is a use-after-free which I've been able to trigger resulting in a splat. To fix this, drop the reference to panfrost_priv in the job structure and add a direct reference to the MMU structure which is what's actually needed. Fixes: 7fdc48cc63a3 ("drm/panfrost: Make sure MMU context lifetime is not b= ound to panfrost_priv") Signed-off-by: Steven Price Acked-by: Alyssa Rosenzweig --- drivers/gpu/drm/panfrost/panfrost_drv.c | 5 +++-- drivers/gpu/drm/panfrost/panfrost_job.c | 6 +++--- drivers/gpu/drm/panfrost/panfrost_job.h | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panf= rost/panfrost_drv.c index 7fcbc2a5b6cd..087e69b98d06 100644 --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -233,6 +233,7 @@ static int panfrost_ioctl_submit(struct drm_device *dev= , void *data, struct drm_file *file) { struct panfrost_device *pfdev =3D dev->dev_private; + struct panfrost_file_priv *file_priv =3D file->driver_priv; struct drm_panfrost_submit *args =3D data; struct drm_syncobj *sync_out =3D NULL; struct panfrost_job *job; @@ -262,12 +263,12 @@ static int panfrost_ioctl_submit(struct drm_device *d= ev, void *data, job->jc =3D args->jc; job->requirements =3D args->requirements; job->flush_id =3D panfrost_gpu_get_latest_flush_id(pfdev); - job->file_priv =3D file->driver_priv; + job->mmu =3D file_priv->mmu; =20 slot =3D panfrost_job_get_slot(job); =20 ret =3D drm_sched_job_init(&job->base, - &job->file_priv->sched_entity[slot], + &file_priv->sched_entity[slot], NULL); if (ret) goto out_put_job; diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panf= rost/panfrost_job.c index fda5871aebe3..7c4208476fbd 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -201,7 +201,7 @@ static void panfrost_job_hw_submit(struct panfrost_job = *job, int js) return; } =20 - cfg =3D panfrost_mmu_as_get(pfdev, job->file_priv->mmu); + cfg =3D panfrost_mmu_as_get(pfdev, job->mmu); =20 job_write(pfdev, JS_HEAD_NEXT_LO(js), lower_32_bits(jc_head)); job_write(pfdev, JS_HEAD_NEXT_HI(js), upper_32_bits(jc_head)); @@ -435,7 +435,7 @@ static void panfrost_job_handle_err(struct panfrost_dev= ice *pfdev, job->jc =3D 0; } =20 - panfrost_mmu_as_put(pfdev, job->file_priv->mmu); + panfrost_mmu_as_put(pfdev, job->mmu); panfrost_devfreq_record_idle(&pfdev->pfdevfreq); =20 if (signal_fence) @@ -456,7 +456,7 @@ static void panfrost_job_handle_done(struct panfrost_de= vice *pfdev, * happen when we receive the DONE interrupt while doing a GPU reset). */ job->jc =3D 0; - panfrost_mmu_as_put(pfdev, job->file_priv->mmu); + panfrost_mmu_as_put(pfdev, job->mmu); panfrost_devfreq_record_idle(&pfdev->pfdevfreq); =20 dma_fence_signal_locked(job->done_fence); diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panf= rost/panfrost_job.h index 77e6d0e6f612..8becc1ba0eb9 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.h +++ b/drivers/gpu/drm/panfrost/panfrost_job.h @@ -17,7 +17,7 @@ struct panfrost_job { struct kref refcount; =20 struct panfrost_device *pfdev; - struct panfrost_file_priv *file_priv; + struct panfrost_mmu *mmu; =20 /* Fence to be signaled by IRQ handler when the job is complete. */ struct dma_fence *done_fence; --=20 2.30.2