[PATCH AUTOSEL 5.7 096/274] media: staging/intel-ipu3: Implement lock for stream on/off operations

Sasha Levin
2020-06-09T00:55:27Z

From: Bingbu Cao <bingbu.cao@intel.com>

[ Upstream commit 33e3c349b2bf1235be458df09fb8d237141486c4 ]

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 <laurent.pinchart@ideasonboard.com>
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/staging/media/ipu3/ipu3-v4l2.c | 10 ++++++++++
drivers/staging/media/ipu3/ipu3.c | 3 +++
drivers/staging/media/ipu3/ipu3.h | 4 ++++
3 files changed, 17 insertions(+)

diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c
index 09c8ede1457c..db8b5d13631a 100644
--- a/drivers/staging/media/ipu3/ipu3-v4l2.c
+++ b/drivers/staging/media/ipu3/ipu3-v4l2.c
@@ -367,8 +367,10 @@ static void imgu_vb2_buf_queue(struct vb2_buffer *vb)

vb2_set_plane_payload(vb, 0, need_bytes);

+ mutex_lock(&imgu->streaming_lock);
if (imgu->streaming)
imgu_queue_buffers(imgu, false, node->pipe);
+ mutex_unlock(&imgu->streaming_lock);

dev_dbg(&imgu->pci_dev->dev, "%s for pipe %u node %u", __func__,
node->pipe, node->id);
@@ -468,10 +470,13 @@ static int imgu_vb2_start_streaming(struct vb2_queue *vq, unsigned int count)
dev_dbg(dev, "%s node name %s pipe %u id %u", __func__,
node->name, node->pipe, node->id);

+ mutex_lock(&imgu->streaming_lock);
if (imgu->streaming) {
r = -EBUSY;
+ mutex_unlock(&imgu->streaming_lock);
goto fail_return_bufs;
}
+ mutex_unlock(&imgu->streaming_lock);

if (!node->enabled) {
dev_err(dev, "IMGU node is not enabled");
@@ -498,9 +503,11 @@ static int imgu_vb2_start_streaming(struct vb2_queue *vq, unsigned int count)

/* Start streaming of the whole pipeline now */
dev_dbg(dev, "IMGU streaming is ready to start");
+ mutex_lock(&imgu->streaming_lock);
r = imgu_s_stream(imgu, true);
if (!r)
imgu->streaming = true;
+ mutex_unlock(&imgu->streaming_lock);

return 0;

@@ -532,6 +539,7 @@ static void imgu_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 && imgu_all_nodes_streaming(imgu, node)) {
/* Yes, really stop streaming now */
@@ -542,6 +550,8 @@ static void imgu_vb2_stop_streaming(struct vb2_queue *vq)
}

imgu_return_all_buffers(imgu, node, VB2_BUF_STATE_ERROR);
+ mutex_unlock(&imgu->streaming_lock);
+
media_pipeline_stop(&node->vdev.entity);
}

diff --git a/drivers/staging/media/ipu3/ipu3.c b/drivers/staging/media/ipu3/ipu3.c
index 7a1d1881483b..ee1bba6bdcac 100644
--- a/drivers/staging/media/ipu3/ipu3.c
+++ b/drivers/staging/media/ipu3/ipu3.c
@@ -675,6 +675,7 @@ 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);

@@ -738,6 +739,7 @@ static int imgu_pci_probe(struct pci_dev *pci_dev,
out_css_powerdown:
imgu_css_set_powerdown(&pci_dev->dev, imgu->base);
out_mutex_destroy:
+ mutex_destroy(&imgu->streaming_lock);
mutex_destroy(&imgu->lock);

return r;
@@ -755,6 +757,7 @@ static void imgu_pci_remove(struct pci_dev *pci_dev)
imgu_css_set_powerdown(&pci_dev->dev, imgu->base);
imgu_dmamap_exit(imgu);
imgu_mmu_exit(imgu->mmu);
+ mutex_destroy(&imgu->streaming_lock);
mutex_destroy(&imgu->lock);
}

diff --git a/drivers/staging/media/ipu3/ipu3.h b/drivers/staging/media/ipu3/ipu3.h
index 73b123b2b8a2..8cd6a0077d99 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;
+
/* Forbid streaming and buffer queuing during system suspend. */
atomic_t qbuf_barrier;
/* Indicate if system suspend take place while imgu is streaming. */
--
2.25.1