From 81f3affa19d6ab0c32aef46b053838219eef7e71 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Thu, 20 Apr 2023 10:45:59 +0100 Subject: [PATCH] media: uvcvideo: Don't expose unsupported formats to userspace When the uvcvideo driver encounters a format descriptor with an unknown format GUID, it creates a corresponding struct uvc_format instance with the fcc field set to 0. Since commit 50459f103edf ("media: uvcvideo: Remove format descriptions"), the driver relies on the V4L2 core to provide the format description string, which the V4L2 core can't do without a valid 4CC. This triggers a WARN_ON. As a format with a zero 4CC can't be selected, it is unusable for applications. Ignore the format completely without creating a uvc_format instance, which fixes the warning. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217252 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2180107 Fixes: 50459f103edf ("media: uvcvideo: Remove format descriptions") Signed-off-by: Laurent Pinchart Reviewed-by: Ricardo Ribalda Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/uvc/uvc_driver.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index 7aefa76..d631ce4 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -251,14 +251,17 @@ static int uvc_parse_format(struct uvc_device *dev, /* Find the format descriptor from its GUID. */ fmtdesc = uvc_format_by_guid(&buffer[5]); - if (fmtdesc != NULL) { - format->fcc = fmtdesc->fcc; - } else { + if (!fmtdesc) { + /* + * Unknown video formats are not fatal errors, the + * caller will skip this descriptor. + */ dev_info(&streaming->intf->dev, "Unknown video format %pUl\n", &buffer[5]); - format->fcc = 0; + return 0; } + format->fcc = fmtdesc->fcc; format->bpp = buffer[21]; /* @@ -675,7 +678,7 @@ static int uvc_parse_streaming(struct uvc_device *dev, interval = (u32 *)&frame[nframes]; streaming->format = format; - streaming->nformats = nformats; + streaming->nformats = 0; /* Parse the format descriptors. */ while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE) { @@ -689,7 +692,10 @@ static int uvc_parse_streaming(struct uvc_device *dev, &interval, buffer, buflen); if (ret < 0) goto error; + if (!ret) + break; + streaming->nformats++; frame += format->nframes; format++; -- 2.7.4