usb: gadget: uvc: Fix ERR_PTR dereference in uvc_v4l2.c

Fix potential dereferencing of ERR_PTR() in find_format_by_pix()
and uvc_v4l2_enum_format().

Fix the following smatch errors:

drivers/usb/gadget/function/uvc_v4l2.c:124 find_format_by_pix()
error: 'fmtdesc' dereferencing possible ERR_PTR()

drivers/usb/gadget/function/uvc_v4l2.c:392 uvc_v4l2_enum_format()
error: 'fmtdesc' dereferencing possible ERR_PTR()

Also, fix similar issue in uvc_v4l2_try_format() for potential
dereferencing of ERR_PTR().

Signed-off-by: Abhishek Tamboli <abhishektamboli9@gmail.com>
Link: https://lore.kernel.org/r/20240815102202.594812-1-abhishektamboli9@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index a024aecb76dc370bffdbd00cdc7e3845993029ea..de1736f834e6b8fedc41ac47af19e48a4409a45c 100644 (file)
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -121,6 +121,9 @@ static struct uvcg_format *find_format_by_pix(struct uvc_device *uvc,
        list_for_each_entry(format, &uvc->header->formats, entry) {
                const struct uvc_format_desc *fmtdesc = to_uvc_format(format->fmt);
 
+               if (IS_ERR(fmtdesc))
+                       continue;
+
                if (fmtdesc->fcc == pixelformat) {
                        uformat = format->fmt;
                        break;
@@ -240,6 +243,7 @@ uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)
        struct uvc_video *video = &uvc->video;
        struct uvcg_format *uformat;
        struct uvcg_frame *uframe;
+       const struct uvc_format_desc *fmtdesc;
        u8 *fcc;
 
        if (fmt->type != video->queue.queue.type)
@@ -277,7 +281,10 @@ uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)
                fmt->fmt.pix.height = uframe->frame.w_height;
                fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(uformat, uframe);
                fmt->fmt.pix.sizeimage = uvc_get_frame_size(uformat, uframe);
-               fmt->fmt.pix.pixelformat = to_uvc_format(uformat)->fcc;
+               fmtdesc = to_uvc_format(uformat);
+               if (IS_ERR(fmtdesc))
+                       return PTR_ERR(fmtdesc);
+               fmt->fmt.pix.pixelformat = fmtdesc->fcc;
        }
        fmt->fmt.pix.field = V4L2_FIELD_NONE;
        fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
@@ -389,6 +396,9 @@ uvc_v4l2_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
                return -EINVAL;
 
        fmtdesc = to_uvc_format(uformat);
+       if (IS_ERR(fmtdesc))
+               return PTR_ERR(fmtdesc);
+
        f->pixelformat = fmtdesc->fcc;
 
        return 0;