From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: David Hildenbrand <david@redhat.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Hanjun Guo <guohanjun@huawei.com>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
virtualization@lists.linux-foundation.org, linux-mm@kvack.org
Subject: [PATCH v2 2/3] virtio-mem: disallow mapping virtio-mem memory via /dev/mem
Date: Mon, 16 Aug 2021 16:25:04 +0200 [thread overview]
Message-ID: <20210816142505.28359-3-david@redhat.com> (raw)
In-Reply-To: <20210816142505.28359-1-david@redhat.com>
By creating our parent IORESOURCE_SYSTEM_RAM resource with
IORESOURCE_EXCLUSIVE, we will disallow any /dev/mem access to our
device-managed region.
Note that access to the region would still be possible if someone simply
doesn't load the virtio-mem driver; however, there is no way of
protecting against someone that just wants to do nasty things.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
drivers/virtio/virtio_mem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 09ed55de07d7..c8f914700a42 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -2516,8 +2516,10 @@ static int virtio_mem_create_resource(struct virtio_mem *vm)
if (!name)
return -ENOMEM;
+ /* Disallow mapping device memory via /dev/mem completely. */
vm->parent_resource = __request_mem_region(vm->addr, vm->region_size,
- name, IORESOURCE_SYSTEM_RAM);
+ name, IORESOURCE_SYSTEM_RAM |
+ IORESOURCE_EXCLUSIVE);
if (!vm->parent_resource) {
kfree(name);
dev_warn(&vm->vdev->dev, "could not reserve device region\n");
--
2.31.1
next prev parent reply other threads:[~2021-08-16 14:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 14:25 [PATCH v2 0/3] virtio-mem: disallow mapping virtio-mem memory via /dev/mem David Hildenbrand
2021-08-16 14:25 ` [PATCH v2 1/3] /dev/mem: disallow access to explicitly excluded system RAM regions David Hildenbrand
2021-08-25 0:58 ` Dan Williams
2021-08-25 7:23 ` David Hildenbrand
2021-08-25 17:07 ` Dan Williams
2021-08-25 17:27 ` David Hildenbrand
2021-08-16 14:25 ` David Hildenbrand [this message]
2021-08-16 14:25 ` [PATCH v2 3/3] kernel/resource: cleanup and optimize iomem_is_exclusive() David Hildenbrand
2021-08-23 19:14 ` [PATCH v2 0/3] virtio-mem: disallow mapping virtio-mem memory via /dev/mem David Hildenbrand
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