vdec_start_streaming() launches a recycle thread when required by the
codec. If kthread_run() fails, the previous error path only powered off
the hardware, leaving sess->priv and codec state allocated. This caused
a permanent leak of the codec context and associated DMA buffers.

Fix this by introducing a dedicated err_cleanup path:

- Call codec_ops->stop() to release the codec context and clear sess->priv.
- Power off the hardware before freeing buffers to avoid DMA faults.
- Free canvas IDs explicitly and set sess->vififo_vaddr = NULL after
  dma_free_coherent() to guard against double‑free in fallback stop paths.
- Reset core->cur_sess and sess->status to prevent stale references.

Following change closes the memory leak on kthread_run() failure and ensures
robust cleanup of codec resources in both error and stop paths.

Cc: Nicolas Dufresne <[email protected]>
Reported-by: Sashiko <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Fixes: 3e7f51bd9607 ("media: meson: add v4l2 m2m video decoder driver")
Signed-off-by: Anand Moon <[email protected]>
---
 drivers/staging/media/meson/vdec/vdec.c | 26 ++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/meson/vdec/vdec.c 
b/drivers/staging/media/meson/vdec/vdec.c
index 7233000e2232..8a5bf1a96830 100644
--- a/drivers/staging/media/meson/vdec/vdec.c
+++ b/drivers/staging/media/meson/vdec/vdec.c
@@ -32,6 +32,8 @@ struct dummy_buf {
 /* 16 MiB for parsed bitstream swap exchange */
 #define SIZE_VIFIFO SZ_16M
 
+static void vdec_free_canvas(struct amvdec_session *sess);
+
 static u32 get_output_size(u32 width, u32 height)
 {
        return ALIGN(width * height, SZ_64K);
@@ -352,16 +354,31 @@ static int vdec_start_streaming(struct vb2_queue *q, 
unsigned int count)
 
        sess->sequence_cap = 0;
        sess->sequence_out = 0;
-       if (vdec_codec_needs_recycle(sess))
+       if (vdec_codec_needs_recycle(sess)) {
                sess->recycle_thread = kthread_run(vdec_recycle_thread, sess,
                                                   "vdec_recycle");
+               if (IS_ERR(sess->recycle_thread)) {
+                       ret = PTR_ERR(sess->recycle_thread);
+                       sess->recycle_thread = NULL;
+                       goto err_cleanup;
+               }
+       }
 
        schedule_work(&sess->esparser_queue_work);
        return 0;
 
+err_cleanup:
+       vdec_free_canvas(sess);
+       vdec_poweroff(sess);
+       if (codec_ops && codec_ops->stop && sess->priv) {
+               codec_ops->stop(sess);
+               kfree(sess->priv);
+               sess->priv = NULL;
+       }
 vififo_free:
        dma_free_coherent(sess->core->dev, sess->vififo_size,
                          sess->vififo_vaddr, sess->vififo_paddr);
+       sess->vififo_vaddr = NULL;
 bufs_done:
        mutex_lock(&core->lock);
        if (core->cur_sess == sess)
@@ -441,8 +458,11 @@ static void vdec_stop_streaming(struct vb2_queue *q)
 
                vdec_poweroff(sess);
                vdec_free_canvas(sess);
-               dma_free_coherent(sess->core->dev, sess->vififo_size,
-                                 sess->vififo_vaddr, sess->vififo_paddr);
+               if (sess->vififo_vaddr) {
+                       dma_free_coherent(sess->core->dev, sess->vififo_size,
+                                         sess->vififo_vaddr,
+                                         sess->vififo_paddr);
+               }
                vdec_reset_timestamps(sess);
                vdec_reset_bufs_recycle(sess);
                kfree(sess->priv);
-- 
2.50.1

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