From c35e7c7a004ef379a1ae7c7486d4829419acad1d Mon Sep 17 00:00:00 2001 From: Ludwig Disterhof Date: Mon, 28 Apr 2025 20:16:50 +0200 Subject: [PATCH] media: usbtv: Lock resolution while streaming commit 7e40e0bb778907b2441bff68d73c3eb6b6cd319f upstream. 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: stable@vger.kernel.org Signed-off-by: Ludwig Disterhof Signed-off-by: Hans Verkuil [hverkuil: call vb2_is_busy instead of vb2_is_streaming] Signed-off-by: Greg Kroah-Hartman --- 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 b249f037900c..d62a960bb5e7 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