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

[Umang Jain]

Hello,

On 3/31/22 21:15, Laurent Pinchart via libcamera-devel wrote:
> The errno variable can potentially be overwritten by operator<<(). Store


Ah good to know!

> it in a local variable before logging the error message.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>


Reviewed-by: Umang Jain <umang.jain 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);