On Mon Apr 28 20:16:50 2025 +0200, Ludwig Disterhof wrote:
> When an program is streaming (ffplay) and another program (qv4l2)
> changes the TV standard from NTSC to PAL, the kernel crashes due to trying
> to copy to unmapped memory.
>
> Changing from NTSC to PAL increases the resolution in the usbtv struct,
> but the video plane buffer isn't adjusted, so it overflows.
>
> Fixes: 0e0fe3958fdd13d ("[media] usbtv: Add support for PAL video source")
> Cc: [email protected]
> Signed-off-by: Ludwig Disterhof <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
> [hverkuil: call vb2_is_busy instead of vb2_is_streaming]
Patch committed.
Thanks,
Hans Verkuil
drivers/media/usb/usbtv/usbtv-video.c | 4 ++++
1 file changed, 4 insertions(+)
---
diff --git a/drivers/media/usb/usbtv/usbtv-video.c
b/drivers/media/usb/usbtv/usbtv-video.c
index be22a9697197..de0328100a60 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -73,6 +73,10 @@ static int usbtv_configure_for_norm(struct usbtv *usbtv,
v4l2_std_id norm)
}
if (params) {
+ if (vb2_is_busy(&usbtv->vb2q) &&
+ (usbtv->width != params->cap_width ||
+ usbtv->height != params->cap_height))
+ return -EBUSY;
usbtv->width = params->cap_width;
usbtv->height = params->cap_height;
usbtv->n_chunks = usbtv->width * usbtv->height
