RE: [PATCH] RDMA/rxe: Return -EFAULT if copy_from_user() fails

From: Yanjun Zhu <yanjunz@mellanox.com>
To: Leon Romanovsky <leon@kernel.org>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Jason Gunthorpe <jgg@ziepe.ca>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
	Doug Ledford <dledford@redhat.com>,
	"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
	"kernel-janitors@vger.kernel.org"
	<kernel-janitors@vger.kernel.org>
Subject: RE: [PATCH] RDMA/rxe: Return -EFAULT if copy_from_user() fails
Date: Tue, 12 May 2020 08:33:57 +0000	[thread overview]
Message-ID: <AM6PR05MB62630AC146F51635E181AA44D8BE0@AM6PR05MB6263.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20200512083107.GI4814@unreal>

-----Original Message-----
From: Leon Romanovsky <leon@kernel.org> 
Sent: Tuesday, May 12, 2020 4:31 PM
To: Dan Carpenter <dan.carpenter@oracle.com>; Jason Gunthorpe <jgg@ziepe.ca>
Cc: Yanjun Zhu <yanjunz@mellanox.com>; Sudip Mukherjee <sudipm.mukherjee@gmail.com>; Doug Ledford <dledford@redhat.com>; linux-rdma@vger.kernel.org; kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] RDMA/rxe: Return -EFAULT if copy_from_user() fails

On Tue, May 12, 2020 at 11:17:06AM +0300, Dan Carpenter wrote:
> On Tue, May 12, 2020 at 10:02:03AM +0300, Leon Romanovsky wrote:
> > On Tue, May 12, 2020 at 09:29:36AM +0300, Leon Romanovsky wrote:
> > > On Mon, May 11, 2020 at 09:37:42PM +0300, Dan Carpenter wrote:
> > > > This function used to always return -EINVAL but we updated it to 
> > > > try preserve the error codes.  Unfortunately the copy_to_user() 
> > > > is returning the number of bytes remaining to be copied instead 
> > > > of a negative error code.
> > > >
> > > > Fixes: a3a974b4654d ("RDMA/rxe: Always return ERR_PTR from 
> > > > rxe_create_mmap_info()")
> > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > > ---
> > > >  drivers/infiniband/sw/rxe/rxe_queue.c | 5 +++--
> > > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > >
> > > Thanks,
> > > Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
> >
> > Actually Yanjun is right and "err" can be removed.
> >
> > Thanks
>
> I don't know if the code you guys are looking at is older or newer 
> than linux-next...  :P

> We both looked on rdma-next, but the wrong code was added to -rc.

Yes. I agree with you.

Zhu Yanjun

> Jason, that patch was marked as stable@.

Thanks