linux-kernel - RE: [PATCH v2 02/12] cxl/core: Check physical address before mapping it in devm_cxl_iomap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 20 Oct 2022 17:01:57 -0700
From:   Dan Williams <dan.j.williams@...el.com>
To:     Robert Richter <rrichter@....com>,
        Alison Schofield <alison.schofield@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        "Ira Weiny" <ira.weiny@...el.com>,
        Ben Widawsky <bwidawsk@...nel.org>,
        Dan Williams <dan.j.williams@...el.com>
CC:     <linux-cxl@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        "Davidlohr Bueso" <dave@...olabs.net>,
        Robert Richter <rrichter@....com>
Subject: RE: [PATCH v2 02/12] cxl/core: Check physical address before mapping
 it in devm_cxl_iomap_block()

Robert Richter wrote:
> The physical base address of a CXL range can be invalid and is then
> set to CXL_RESOURCE_NONE. In general software shall prevent such
> situations, but it is hard to proof this may never happen. E.g. in
> add_port_attach_ep() there this the following:
> 
>       component_reg_phys = find_component_registers(uport_dev);
>       port = devm_cxl_add_port(&parent_port->dev, uport_dev,
>               component_reg_phys, parent_dport);
> 
> find_component_registers() and subsequent functions (e.g.
> cxl_regmap_to_base()) may return CXL_RESOURCE_NONE. But it is written
> to port without any further check in cxl_port_alloc():
> 
>       port->component_reg_phys = component_reg_phys;
> 
> It is then later directly used in devm_cxl_setup_hdm() to map io
> ranges with devm_cxl_iomap_block(). Just an example...
> 
> Check this condition. Also do not fail silently like an ioremap()
> failure, use a WARN_ON_ONCE() for it.
> 
> Signed-off-by: Robert Richter <rrichter@....com>

Looks good to me, applied for v6.2