Re: [PATCH] SUNRPC: Add a check for gss_release_msg

From: Greg KH <gregkh@linuxfoundation.org>
To: Aditya Pakki <pakki001@umn.edu>
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
	Chuck Lever <chuck.lever@oracle.com>,
	Trond Myklebust <trond.myklebust@hammerspace.com>,
	Anna Schumaker <anna.schumaker@netapp.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Dave Wysochanski <dwysocha@redhat.com>,
	linux-nfs@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] SUNRPC: Add a check for gss_release_msg
Date: Tue, 20 Apr 2021 09:15:23 +0200	[thread overview]
Message-ID: <YH5/i7OvsjSmqADv@kroah.com> (raw)
In-Reply-To: <20210407001658.2208535-1-pakki001@umn.edu>

On Tue, Apr 06, 2021 at 07:16:56PM -0500, Aditya Pakki wrote:
> In gss_pipe_destroy_msg(), in case of error in msg, gss_release_msg
> deletes gss_msg. The patch adds a check to avoid a potential double
> free.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> ---
>  net/sunrpc/auth_gss/auth_gss.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
> index 5f42aa5fc612..eb52eebb3923 100644
> --- a/net/sunrpc/auth_gss/auth_gss.c
> +++ b/net/sunrpc/auth_gss/auth_gss.c
> @@ -848,7 +848,8 @@ gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
>  			warn_gssd();
>  		gss_release_msg(gss_msg);
>  	}
> -	gss_release_msg(gss_msg);
> +	if (gss_msg)
> +		gss_release_msg(gss_msg);a

If you look at the code, this is impossible to have happen.

Please stop submitting known-invalid patches.  Your professor is playing
around with the review process in order to achieve a paper in some
strange and bizarre way.

This is not ok, it is wasting our time, and we will have to report this,
AGAIN, to your university...

greg k-h