26 Nov
2021
26 Nov
'21
8:51 a.m.
On 26.11.21 03:30, Sasha Levin wrote:
From: David Hildenbrand david@redhat.com
[ Upstream commit 61082ad6a6e1f999eef7e7e90046486c87933b1e ]
The initial virtio-mem spec states that while unplugged memory should not be read, the device still has to allow for reading unplugged memory inside the usable region. The primary motivation for this default handling was to simplify bringup of virtio-mem, because there were corner cases where Linux might have accidentially read unplugged memory inside added Linux memory blocks.
In the meantime, we:
- Removed /dev/kmem in commit bbcd53c96071 ("drivers/char: remove /dev/kmem for good")
- Disallowed access to virtio-mem device memory via /dev/mem in commit 2128f4e21aa2 ("virtio-mem: disallow mapping virtio-mem memory via /dev/mem")
- Sanitized access to virtio-mem device memory via /proc/kcore in commit 0daa322b8ff9 ("fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages")
- Sanitized access to virtio-mem device memory via /proc/vmcore in commit ce2814622e84 ("virtio-mem: kdump mode to sanitize /proc/vmcore access")
As 2. and 4. are part of v5.16-rc1 but not v5.10-stable
Nacked-by: David Hildenbrand david@redhat.com
--
Thanks,
David / dhildenb