Re: [PATCH] SUNRPC: Fix potential memory leak in xs_udp_send_request()

[Jeff Layton]

On Wed, 2022-09-07 at 15:13 +0800, Jianglei Nie wrote:
> xs_udp_send_request() allocates a memory chunk for xdr->bvec with
> xdr_alloc_bvec(). When xprt_sock_sendmsg() finishs, xdr->bvec is not
> released, which will lead to a memory leak.
> 
> we should release the xdr->bvec with xdr_free_bvec() after
> xprt_sock_sendmsg() like bc_sendto() does.
> 
> Signed-off-by: Jianglei Nie <niejianglei2021@xxxxxxx>
> ---
>  net/sunrpc/xprtsock.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index e976007f4fd0..298182a3c168 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -958,6 +958,7 @@ static int xs_udp_send_request(struct rpc_rqst *req)
>  		return status;
>  	req->rq_xtime = ktime_get();
>  	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
> +	xdr_free_bvec(xdr);
>  
>  	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
>  			xdr->len, status);

I think you're probably correct here.

I was thinking we might have a similar bug in svc_tcp_sendmsg, but it
looks like that one gets freed in svc_tcp_sendto.

Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>