[libcamera-devel] [PATCH] libcamera: v4l2_videodevice: Fix potential errno overwrite

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2022-03-31 16:45:26)
> The errno variable can potentially be overwritten by operator<<(). Store
> it in a local variable before logging the error message.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> ---
>  src/libcamera/v4l2_videodevice.cpp | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
> index 009f6d55610f..0830be80c553 100644
> --- a/src/libcamera/v4l2_videodevice.cpp
> +++ b/src/libcamera/v4l2_videodevice.cpp
> @@ -647,14 +647,17 @@ int V4L2VideoDevice::open()
>   */
>  int V4L2VideoDevice::open(SharedFD handle, enum v4l2_buf_type type)
>  {
> +       int ret;
> +
>         UniqueFD newFd = handle.dup();
>         if (!newFd.isValid()) {
> +               ret = -errno;
>                 LOG(V4L2, Error) << "Failed to duplicate file handle: "
> -                                << strerror(errno);
> -               return -errno;
> +                                << strerror(-ret);
> +               return ret;
>         }
>  
> -       int ret = V4L2Device::setFd(std::move(newFd));
> +       ret = V4L2Device::setFd(std::move(newFd));
>         if (ret < 0) {
>                 LOG(V4L2, Error) << "Failed to set file handle: "
>                                  << strerror(-ret);
> -- 
> Regards,
> 
> Laurent Pinchart
>