[libcamera-devel] [PATCH 1/2] libcamera: ipc_unixsocket: Do not run memcpy with null arguments

[Laurent Pinchart]

Hi Umang,

Thank you for the patch.

On Wed, Aug 18, 2021 at 02:08:41PM +0530, Umang Jain wrote:
> In IPCUnixSocket, a payload can be sent/received with empty fd vector,
> which leads to passing a nullptr in memcpy() in both sendData()
> and recvData(). Add a null check for fd vector's data pointer
> to avoid invoking memcpy() with nullptr.
> 
> The issue is noticed by running a test manually testing the vimc
> IPA code paths in isolated mode. It is only noticed when the test
> is compiled with -Db_sanitize=address,undefined meson built-in option.
> 
> ipc_unixsocket.cpp:268:8: runtime error: null pointer passed as argument 2, which is declared to never be null
> ipc_unixsocket.cpp:312:8: runtime error: null pointer passed as argument 1, which is declared to never be null
> 
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  src/libcamera/ipc_unixsocket.cpp | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/libcamera/ipc_unixsocket.cpp b/src/libcamera/ipc_unixsocket.cpp
> index a4ab1a5f..7188cf29 100644
> --- a/src/libcamera/ipc_unixsocket.cpp
> +++ b/src/libcamera/ipc_unixsocket.cpp
> @@ -260,7 +260,8 @@ int IPCUnixSocket::sendData(const void *buffer, size_t length,
>  	msg.msg_control = cmsg;
>  	msg.msg_controllen = cmsg->cmsg_len;
>  	msg.msg_flags = 0;
> -	memcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));
> +	if (fds)
> +		memcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));
>  
>  	if (sendmsg(fd_, &msg, 0) < 0) {
>  		int ret = -errno;
> @@ -304,7 +305,8 @@ int IPCUnixSocket::recvData(void *buffer, size_t length,
>  		return ret;
>  	}
>  
> -	memcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));
> +	if (fds)
> +		memcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));
>  
>  	return 0;
>  }

-- 
Regards,

Laurent Pinchart