From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ben Widawsky <ben.widawsky@intel.com>
Cc: <linux-cxl@vger.kernel.org>, <linux-acpi@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <linux-nvdimm@lists.01.org>,
<linux-pci@vger.kernel.org>, Bjorn Helgaas <helgaas@kernel.org>,
"Chris Browy" <cbrowy@avery-design.com>,
Christoph Hellwig <hch@infradead.org>,
"Dan Williams" <dan.j.williams@intel.com>,
David Hildenbrand <david@redhat.com>,
David Rientjes <rientjes@google.com>,
Ira Weiny <ira.weiny@intel.com>,
"Jon Masters" <jcm@jonmasters.org>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Randy Dunlap <rdunlap@infradead.org>,
Vishal Verma <vishal.l.verma@intel.com>,
"John Groves (jgroves)" <jgroves@micron.com>,
"Kelley, Sean V" <sean.v.kelley@intel.com>,
kernel test robot <lkp@intel.com>
Subject: Re: [PATCH v4 4/9] cxl/mem: Add basic IOCTL interface
Date: Wed, 17 Feb 2021 09:55:24 +0000 [thread overview]
Message-ID: <20210217095524.000071f5@Huawei.com> (raw)
In-Reply-To: <20210216183432.lf2uj63uckogfad4@intel.com>
On Tue, 16 Feb 2021 10:34:32 -0800
Ben Widawsky <ben.widawsky@intel.com> wrote:
...
> > > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> > > index 237b956f0be0..4ca4f5afd9d2 100644
> > > --- a/drivers/cxl/mem.c
> > > +++ b/drivers/cxl/mem.c
> > > @@ -686,7 +686,11 @@ static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm,
> > >
> > > memcpy(out_cmd, c, sizeof(*c));
> > > out_cmd->info.size_in = send_cmd->in.size;
> > > - out_cmd->info.size_out = send_cmd->out.size;
> > > + /*
> > > + * XXX: out_cmd->info.size_out will be controlled by the driver, and the
> > > + * specified number of bytes @send_cmd->out.size will be copied back out
> > > + * to userspace.
> > > + */
> > >
> > > return 0;
> > > }
> >
> > This deals with the buffer overflow being triggered from userspace.
> >
> > I'm still nervous. I really don't like assuming hardware will do the right
> > thing and never send us more data than we expect.
> >
> > Given the check that it will fit in the target buffer is simple,
> > I'd prefer to harden it and know we can't have a problem.
> >
> > Jonathan
>
> I'm working on hardening __cxl_mem_mbox_send_cmd now per your request. With
> that, I think this solves the issue, right?
Should do. Thanks,
Jonathan
next prev parent reply other threads:[~2021-02-17 9:57 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-16 1:45 [PATCH v4 0/9] CXL 2.0 Support Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 1/9] cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 2/9] cxl/mem: Find device capabilities Ben Widawsky
2021-02-16 14:51 ` Jonathan Cameron
2021-02-16 16:43 ` Ben Widawsky
2021-02-16 17:20 ` Jonathan Cameron
2021-02-16 17:56 ` Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 3/9] cxl/mem: Register CXL memX devices Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 4/9] cxl/mem: Add basic IOCTL interface Ben Widawsky
2021-02-16 15:22 ` Jonathan Cameron
2021-02-16 17:53 ` Ben Widawsky
2021-02-16 18:28 ` Jonathan Cameron
2021-02-16 18:34 ` Ben Widawsky
2021-02-17 9:55 ` Jonathan Cameron [this message]
2021-02-16 18:12 ` Al Viro
2021-02-16 18:22 ` Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 5/9] cxl/mem: Add a "RAW" send command Ben Widawsky
2021-02-16 15:30 ` Jonathan Cameron
2021-02-16 18:03 ` Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 6/9] cxl/mem: Enable commands via CEL Ben Widawsky
2021-02-16 15:43 ` Jonathan Cameron
2021-02-16 1:45 ` [PATCH v4 7/9] cxl/mem: Add set of informational commands Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 8/9] MAINTAINERS: Add maintainers of the CXL driver Ben Widawsky
2021-02-16 1:45 ` [PATCH v4 9/9] cxl/mem: Add payload dumping for debug Ben Widawsky
2021-02-16 15:48 ` Jonathan Cameron
2021-02-16 16:48 ` Dan Williams
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