In the Linux kernel, the following vulnerability has been resolved:
x86/ioremap: Map EFI-reserved memory as encrypted for SEV
Some drivers require memory that is marked as EFI boot services
data. In order for this memory to not be re-used by the kernel
after ExitBootServices(), efi_mem_reserve() is used to preserve it
by inserting a new EFI memory descriptor and marking it with the
EFI_MEMORY_RUNTIME attribute.
Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to
be mapped encrypted by Linux, otherwise the kernel might crash at boot
like below:
EFI Variables Facility v0.08 2004-May-17
general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI
CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:efi_mokvar_entry_next
[...]
Call Trace:
efi_mokvar_sysfs_init
? efi_mokvar_table_init
do_one_initcall
? __kmalloc
kernel_init_freeable
? rest_init
kernel_init
ret_from_fork
Expand the __ioremap_check_other() function to additionally check for
this other type of boot data reserved at runtime and indicate that it
should be mapped encrypted for an SEV guest.
[ bp: Massage commit message. ]
Metrics
Affected Vendors & Products
References
History
Thu, 31 Oct 2024 15:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
cvssV3_1
|
ssvc
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-05-21T14:19:32.167Z
Updated: 2024-11-04T12:01:53.370Z
Reserved: 2024-04-10T18:59:19.530Z
Link: CVE-2021-47228
Vulnrichment
Updated: 2024-08-04T05:32:07.392Z
NVD
Status : Awaiting Analysis
Published: 2024-05-21T15:15:12.250
Modified: 2024-10-31T15:35:03.093
Link: CVE-2021-47228
Redhat