5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Valery Borovsky commit fe50cdaebf12cd32ff9a44d92bfd6fbc2300dbd4 upstream. rtl2832_sdr_start_streaming() calls rtl2832_sdr_alloc_stream_bufs(), rtl2832_sdr_alloc_urbs() and rtl2832_sdr_submit_urbs() in sequence and shares a single err: label that only unlocks the mutex and returns. When alloc_urbs() succeeds but submit_urbs() fails, or when alloc_urbs() itself returns -ENOMEM after alloc_stream_bufs() has already succeeded, the URBs and/or the coherent DMA stream buffers stay allocated while streaming reports failure to vb2. Two latent defects follow on the next VIDIOC_STREAMON: 1) rtl2832_sdr_alloc_stream_bufs() unconditionally resets dev->buf_num to 0 and overwrites dev->buf_list[]/dev->dma_addr[], permanently leaking the coherent DMA memory allocated by the previous attempt. 2) rtl2832_sdr_alloc_urbs() never resets dev->urbs_initialized and only increments it. After a second successful pass urbs_initialized can exceed MAX_BULK_BUFS, so the subsequent rtl2832_sdr_free_urbs() walks from urbs_initialized - 1 down to 0 and reads past the end of dev->urb_list[], passing garbage pointers to usb_free_urb(). Mirror the teardown that stop_streaming() already performs: on the error path call rtl2832_sdr_free_urbs() and rtl2832_sdr_free_stream_bufs() before unlocking. Both helpers are idempotent (free_urbs kills and zeros urbs_initialized; free_stream_bufs is gated on URB_BUF and clears the buf_num counter), so partial-failure paths and the no-allocation paths remain safe. Issue identified by automated review of the INV-003 series at https://sashiko.dev/ Fixes: 771138920eaf ("[media] rtl2832_sdr: Realtek RTL2832 SDR driver module") Cc: stable@vger.kernel.org Signed-off-by: Valery Borovsky Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/dvb-frontends/rtl2832_sdr.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/media/dvb-frontends/rtl2832_sdr.c +++ b/drivers/media/dvb-frontends/rtl2832_sdr.c @@ -902,9 +902,12 @@ static int rtl2832_sdr_start_streaming(s goto err; mutex_unlock(&dev->v4l2_lock); + return 0; err: + rtl2832_sdr_free_urbs(dev); + rtl2832_sdr_free_stream_bufs(dev); rtl2832_sdr_cleanup_queued_bufs(dev, VB2_BUF_STATE_QUEUED); mutex_unlock(&dev->v4l2_lock);