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[209.132.180.67]) by mx.google.com with ESMTP id j39si978702plb.272.2019.01.30.01.00.58; Wed, 30 Jan 2019 01:01:14 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730483AbfA3I7L (ORCPT + 99 others); Wed, 30 Jan 2019 03:59:11 -0500 Received: from mga05.intel.com ([192.55.52.43]:11355 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730331AbfA3I7H (ORCPT ); Wed, 30 Jan 2019 03:59:07 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jan 2019 00:59:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,540,1539673200"; d="scan'208";a="295606398" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga005.jf.intel.com with ESMTP; 30 Jan 2019 00:59:03 -0800 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id 0B489203F8; Wed, 30 Jan 2019 10:59:01 +0200 (EET) Date: Wed, 30 Jan 2019 10:59:01 +0200 From: Sakari Ailus To: Rajmohan Mani Cc: Mauro Carvalho Chehab , Greg Kroah-Hartman , linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Jacopo Mondi , tian.shu.qiu@intel.com, bingbu.cao@intel.com, Zhi@paasikivi.fi.intel.com, Yong , hverkuil@xs4all.nl, tfiga@chromium.org Subject: Re: [PATCH] media: staging/intel-ipu3: Implement lock for stream on/off operations Message-ID: <20190130085901.w2ogdoax7t4yfyj6@paasikivi.fi.intel.com> References: <20190129222736.6216-1-rajmohan.mani@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190129222736.6216-1-rajmohan.mani@intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rajmohan, On Tue, Jan 29, 2019 at 02:27:36PM -0800, Rajmohan Mani wrote: > Currently concurrent stream off operations on ImgU nodes are not > synchronized, leading to use-after-free bugs (as reported by KASAN). > > [ 250.090724] BUG: KASAN: use-after-free in ipu3_dmamap_free+0xc5/0x116 [ipu3_imgu] > [ 250.090726] Read of size 8 at addr ffff888127b29bc0 by task yavta/18836 > [ 250.090731] Hardware name: HP Soraka/Soraka, BIOS Google_Soraka.10431.17.0 03/22/2018 > [ 250.090732] Call Trace: > [ 250.090735] dump_stack+0x6a/0xb1 > [ 250.090739] print_address_description+0x8e/0x279 > [ 250.090743] ? ipu3_dmamap_free+0xc5/0x116 [ipu3_imgu] > [ 250.090746] kasan_report+0x260/0x28a > [ 250.090750] ipu3_dmamap_free+0xc5/0x116 [ipu3_imgu] > [ 250.090754] ipu3_css_pool_cleanup+0x24/0x37 [ipu3_imgu] > [ 250.090759] ipu3_css_pipeline_cleanup+0x61/0xb9 [ipu3_imgu] > [ 250.090763] ipu3_css_stop_streaming+0x1f2/0x321 [ipu3_imgu] > [ 250.090768] imgu_s_stream+0x94/0x443 [ipu3_imgu] > [ 250.090772] ? ipu3_vb2_buf_queue+0x280/0x280 [ipu3_imgu] > [ 250.090775] ? vb2_dma_sg_unmap_dmabuf+0x16/0x6f [videobuf2_dma_sg] > [ 250.090778] ? vb2_buffer_in_use+0x36/0x58 [videobuf2_common] > [ 250.090782] ipu3_vb2_stop_streaming+0xf9/0x135 [ipu3_imgu] > > Implemented a lock to synchronize imgu stream on / off operations and > the modification of streaming flag (in struct imgu_device), to prevent > these issues. > > Reported-by: Laurent Pinchart > Suggested-by: Laurent Pinchart > > Signed-off-by: Rajmohan Mani > --- > drivers/staging/media/ipu3/ipu3-v4l2.c | 6 ++++++ > drivers/staging/media/ipu3/ipu3.c | 3 +++ > drivers/staging/media/ipu3/ipu3.h | 4 ++++ > 3 files changed, 13 insertions(+) > > diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c > index c7936032beb9..cf7e917cd0c8 100644 > --- a/drivers/staging/media/ipu3/ipu3-v4l2.c > +++ b/drivers/staging/media/ipu3/ipu3-v4l2.c > @@ -507,12 +507,15 @@ static int ipu3_vb2_start_streaming(struct vb2_queue *vq, unsigned int count) > goto fail_stop_pipeline; > } > > + mutex_lock(&imgu->streaming_lock); > + You appear to be using imgu_device.lock (while searching buffers to queue to the device) as well as imgu_video_device.lock (qbuf, dqbuf) to serialise access to imgu_video_device.buffers list. The two locks may be acquired at the same time but each by different processes. That needs to be addressed, but probably not in this patch. I wonder if it'd be more simple to use imgu->lock here instead of adding a new one. > /* Start streaming of the whole pipeline now */ > dev_dbg(dev, "IMGU streaming is ready to start"); > r = imgu_s_stream(imgu, true); > if (!r) > imgu->streaming = true; > > + mutex_unlock(&imgu->streaming_lock); > return 0; > > fail_stop_pipeline: > @@ -543,6 +546,8 @@ static void ipu3_vb2_stop_streaming(struct vb2_queue *vq) > dev_err(&imgu->pci_dev->dev, > "failed to stop subdev streaming\n"); > > + mutex_lock(&imgu->streaming_lock); > + > /* Was this the first node with streaming disabled? */ > if (imgu->streaming && ipu3_all_nodes_streaming(imgu, node)) { > /* Yes, really stop streaming now */ > @@ -552,6 +557,7 @@ static void ipu3_vb2_stop_streaming(struct vb2_queue *vq) > imgu->streaming = false; > } > > + mutex_unlock(&imgu->streaming_lock); > ipu3_return_all_buffers(imgu, node, VB2_BUF_STATE_ERROR); > media_pipeline_stop(&node->vdev.entity); > } > diff --git a/drivers/staging/media/ipu3/ipu3.c b/drivers/staging/media/ipu3/ipu3.c > index d521b3afb8b1..2daee51cd845 100644 > --- a/drivers/staging/media/ipu3/ipu3.c > +++ b/drivers/staging/media/ipu3/ipu3.c > @@ -635,6 +635,7 @@ static int imgu_pci_probe(struct pci_dev *pci_dev, > return r; > > mutex_init(&imgu->lock); > + mutex_init(&imgu->streaming_lock); > atomic_set(&imgu->qbuf_barrier, 0); > init_waitqueue_head(&imgu->buf_drain_wq); > > @@ -699,6 +700,7 @@ static int imgu_pci_probe(struct pci_dev *pci_dev, > ipu3_css_set_powerdown(&pci_dev->dev, imgu->base); > out_mutex_destroy: > mutex_destroy(&imgu->lock); > + mutex_destroy(&imgu->streaming_lock); > > return r; > } > @@ -716,6 +718,7 @@ static void imgu_pci_remove(struct pci_dev *pci_dev) > ipu3_dmamap_exit(imgu); > ipu3_mmu_exit(imgu->mmu); > mutex_destroy(&imgu->lock); > + mutex_destroy(&imgu->streaming_lock); > } > > static int __maybe_unused imgu_suspend(struct device *dev) > diff --git a/drivers/staging/media/ipu3/ipu3.h b/drivers/staging/media/ipu3/ipu3.h > index 04fc99f47ebb..f732315f0701 100644 > --- a/drivers/staging/media/ipu3/ipu3.h > +++ b/drivers/staging/media/ipu3/ipu3.h > @@ -146,6 +146,10 @@ struct imgu_device { > * vid_buf.list and css->queue > */ > struct mutex lock; > + > + /* Lock to protect writes to streaming flag in this struct */ > + struct mutex streaming_lock; > + > /* Forbit streaming and buffer queuing during system suspend. */ > atomic_t qbuf_barrier; > /* Indicate if system suspend take place while imgu is streaming. */ -- Regards, Sakari Ailus sakari.ailus@linux.intel.com