[PATCH v2] media: cx231xx-audio: drain wq_trigger before audio fini

[Fan Wu]

audio_trigger() is deferred work (dev->wq_trigger) armed from
snd_cx231xx_capture_trigger() on every PCM START/STOP; it dereferences
dev->adev state and may free the URBs via cx231xx_isoc_audio_deinit().
cx231xx_audio_fini() tore down that state without draining wq_trigger,
so work armed before or racing fini ran against freed state.

Use disable_work_sync() in fini to drain the work and prevent further
queueing.  Initialize the work, lock and stream_started counter at the
top of cx231xx_audio_init(), before any fallible allocation, and clear
the partially-built audio state on its error path, so fini is safe even
if a later step fails.

This issue was found by an in-house static analysis tool.

Fixes: 61b04cb24a12 ("[media] cx231xx-audio: fix some locking issues")
Cc: stable@xxxxxxxxxxxxxxx # needs adjustments for <= 6.6: use cancel_work_sync()
Link: https://lore.kernel.org/r/8c7e1294-b906-4636-890c-b64d03b0e1d0@xxxxxxxxxx
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@xxxxxxxxxx>
---
Changes in v2: use disable_work_sync() instead of a teardown flag +
cancel_work_sync(), as suggested by Hans Verkuil.  The init-ordering
fix and error-path cleanup from v1 are retained.
---
 drivers/media/platform/ti/vpe/vip.c   | 37 ++++++++++++++++++++++++---
 drivers/media/platform/ti/vpe/vpdma.c |  3 ++-
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/ti/vpe/vip.c b/drivers/media/platform/ti/vpe/vip.c
index cb0a5a07a3d4..30e9a85d4cf5 100644
--- a/drivers/media/platform/ti/vpe/vip.c
+++ b/drivers/media/platform/ti/vpe/vip.c
@@ -814,6 +814,22 @@ static void clear_irqs(struct vip_dev *dev, int irq_num, int list_num)
 	vpdma_clear_list_stat(dev->shared->vpdma, irq_num, dev->slice_id);
 }
 
+/*
+ * Quiesce recovery work and per-list IRQs before releasing stream resources.
+ * disable_work_sync() prevents the overflow handler from requeueing recovery
+ * work. Mask and synchronize IRQs afterwards because a running worker may
+ * have re-enabled them before exiting.
+ */
+static void vip_quiesce_stream(struct vip_stream *stream)
+{
+	struct vip_dev *dev = stream->port->dev;
+
+	disable_work_sync(&stream->recovery_work);
+	disable_irqs(dev, dev->slice_id, stream->list_num);
+	clear_irqs(dev, dev->slice_id, stream->list_num);
+	synchronize_irq(dev->irq);
+}
+
 static void populate_desc_list(struct vip_stream *stream)
 {
 	struct vip_port *port = stream->port;
@@ -2428,6 +2444,7 @@ static int vip_start_streaming(struct vb2_queue *vq, unsigned int count)
 		goto err;
 
 	stream->num_recovery = 0;
+	enable_work(&stream->recovery_work);
 
 	clear_irqs(dev, dev->slice_id, stream->list_num);
 	enable_irqs(dev, dev->slice_id, stream->list_num);
@@ -2452,13 +2469,17 @@ static void vip_stop_streaming(struct vb2_queue *vq)
 	struct vip_dev *dev = port->dev;
 	int ret;
 
+	/*
+	 * A running recovery worker may re-enable the parser, so quiesce it
+	 * and its IRQ handler before stopping the parser or releasing the
+	 * descriptor list.
+	 */
+	vip_quiesce_stream(stream);
+
 	vip_parser_stop_imm(port, true);
 	vip_enable_parser(port, false);
 	unset_fmt_params(stream);
 
-	disable_irqs(dev, dev->slice_id, stream->list_num);
-	clear_irqs(dev, dev->slice_id, stream->list_num);
-
 	if (port->subdev) {
 		ret = v4l2_subdev_call(port->subdev, video, s_stream, 0);
 		if (ret)
@@ -3074,6 +3095,8 @@ static int alloc_stream(struct vip_port *port, int stream_id, int vfl_type)
 		goto do_free_hwlist;
 
 	INIT_WORK(&stream->recovery_work, vip_overflow_recovery_work);
+	/* Start disabled; vip_start_streaming() enables it before IRQs. */
+	disable_work(&stream->recovery_work);
 
 	INIT_LIST_HEAD(&stream->vidq);
 
@@ -3139,6 +3162,13 @@ static void free_stream(struct vip_stream *stream)
 		return;
 
 	dev = stream->port->dev;
+	/*
+	 * Unpublish the stream and quiesce its IRQ handler and recovery worker
+	 * before releasing stream-owned resources.
+	 */
+	stream->port->cap_streams[stream->stream_id] = NULL;
+	vip_quiesce_stream(stream);
+
 	/* Free up the Drop queue */
 	list_for_each_safe(pos, q, &stream->dropq) {
 		buf = list_entry(pos,
@@ -3150,7 +3180,6 @@ static void free_stream(struct vip_stream *stream)
 
 	video_unregister_device(stream->vfd);
 	vpdma_hwlist_release(dev->shared->vpdma, stream->list_num);
-	stream->port->cap_streams[stream->stream_id] = NULL;
 	kfree(stream);
 }
 
diff --git a/drivers/media/platform/ti/vpe/vpdma.c b/drivers/media/platform/ti/vpe/vpdma.c
index 573aa83f62eb..f9f5b2f1ee1a 100644
--- a/drivers/media/platform/ti/vpe/vpdma.c
+++ b/drivers/media/platform/ti/vpe/vpdma.c
@@ -988,7 +988,8 @@ void *vpdma_hwlist_release(struct vpdma_data *vpdma, int list_num)
 
 	spin_lock_irqsave(&vpdma->lock, flags);
 	vpdma->hwlist_used[list_num] = false;
-	priv = vpdma->hwlist_priv;
+	priv = vpdma->hwlist_priv[list_num];
+	vpdma->hwlist_priv[list_num] = NULL;
 	spin_unlock_irqrestore(&vpdma->lock, flags);
 
 	return priv;
-- 
2.34.1