// For flags

CVE-2021-47389

KVM: SVM: fix missing sev_decommission in sev_receive_start

Severity Score

5.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

KVM: SVM: fix missing sev_decommission in sev_receive_start

DECOMMISSION the current SEV context if binding an ASID fails after
RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest
context and thus needs to be paired with DECOMMISSION:

The RECEIVE_START command is the only command other than the LAUNCH_START
command that generates a new guest context and guest handle.

The missing DECOMMISSION can result in subsequent SEV launch failures,
as the firmware leaks memory and might not able to allocate more SEV
guest contexts in the future.

Note, LAUNCH_START suffered the same bug, but was previously fixed by
commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID
binding fails").

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: SVM: corrige la falta de sev_decommission en sev_receive_start DESCOMMISSION el contexto SEV actual si falla la vinculación de un ASID después de RECEIVE_START. Según la API SEV de AMD, RECEIVE_START genera un nuevo contexto de invitado y, por lo tanto, debe combinarse con DECOMMISSION: el comando RECEIVE_START es el único comando, además del comando LAUNCH_START, que genera un nuevo contexto de invitado y un identificador de invitado. La DESCOMISIÓN faltante puede provocar fallas de inicio de SEV posteriores, ya que el firmware pierde memoria y es posible que no pueda asignar más contextos de invitados de SEV en el futuro. Tenga en cuenta que LAUNCH_START sufrió el mismo error, pero se solucionó previamente mediante la confirmación 934002cd660b ("KVM: SVM: llame a SEV Guest Decommission si falla el enlace ASID").

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-21 CVE Reserved
  • 2024-05-21 CVE Published
  • 2024-05-22 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-772: Missing Release of Resource after Effective Lifetime
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.13 < 5.14.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.13 < 5.14.10"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.13 < 5.15
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.13 < 5.15"
en
Affected