Re: [PATCH 2/2] xprtrdma: Double free in rpcrdma_sendctxs_create()

["Schumaker, Anna" <Anna.Schumaker@netapp.com>]

On Mon, 2019-01-07 at 12:22 -0500, Bruce Fields wrote:
> On Sat, Jan 05, 2019 at 11:24:45AM -0500, Chuck Lever wrote:
> > > On Jan 5, 2019, at 8:06 AM, Dan Carpenter <dan.carpenter@oracle.com>
> > > wrote:
> > > 
> > > The clean up is handled by the caller, rpcrdma_buffer_create(), so this
> > > call to rpcrdma_sendctxs_destroy() leads to a double free.
> > 
> > True. This fix is adequate, but I'm wondering if rpcrdma_sendctxs_destroy
> > should be made more careful about being called twice. Hm.
> > 
> > Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
> 
> I'm assuming Trond or Anna will pick this up.--b.

Yeah, I'll take this one and 1/2 for a 5.0-rc.  I might save the additional
cleanup patch Dan sent for 5.1

Anna

> 
> > 
> > > Fixes: ae72950abf99 ("xprtrdma: Add data structure to manage RDMA Send
> > > arguments")
> > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > ---
> > > net/sunrpc/xprtrdma/verbs.c | 6 +-----
> > > 1 file changed, 1 insertion(+), 5 deletions(-)
> > > 
> > > diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> > > index 3dde05892c8e..4994e75945b8 100644
> > > --- a/net/sunrpc/xprtrdma/verbs.c
> > > +++ b/net/sunrpc/xprtrdma/verbs.c
> > > @@ -845,17 +845,13 @@ static int rpcrdma_sendctxs_create(struct
> > > rpcrdma_xprt *r_xprt)
> > > 	for (i = 0; i <= buf->rb_sc_last; i++) {
> > > 		sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
> > > 		if (!sc)
> > > -			goto out_destroy;
> > > +			return -ENOMEM;
> > > 
> > > 		sc->sc_xprt = r_xprt;
> > > 		buf->rb_sc_ctxs[i] = sc;
> > > 	}
> > > 
> > > 	return 0;
> > > -
> > > -out_destroy:
> > > -	rpcrdma_sendctxs_destroy(buf);
> > > -	return -ENOMEM;
> > > }
> > > 
> > > /* The sendctx queue is not guaranteed to have a size that is a
> > > -- 
> > > 2.17.1
> > > 
> > 
> > --
> > Chuck Lever
> > 
> >