linux-cve-announce - CVE-2023-54296: KVM: SVM: Get source vCPUs from source VM for SEV-ES intrahost migration

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Message-ID: <2025123031-CVE-2023-54296-e667@gregkh>
Date: Tue, 30 Dec 2025 13:23:49 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-54296: KVM: SVM: Get source vCPUs from source VM for SEV-ES intrahost migration

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

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

KVM: SVM: Get source vCPUs from source VM for SEV-ES intrahost migration

Fix a goof where KVM tries to grab source vCPUs from the destination VM
when doing intrahost migration.  Grabbing the wrong vCPU not only hoses
the guest, it also crashes the host due to the VMSA pointer being left
NULL.

  BUG: unable to handle page fault for address: ffffe38687000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP NOPTI
  CPU: 39 PID: 17143 Comm: sev_migrate_tes Tainted: GO       6.5.0-smp--fff2e47e6c3b-next #151
  Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.28.0 07/10/2023
  RIP: 0010:__free_pages+0x15/0xd0
  RSP: 0018:ffff923fcf6e3c78 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffffe38687000000 RCX: 0000000000000100
  RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffe38687000000
  RBP: ffff923fcf6e3c88 R08: ffff923fcafb0000 R09: 0000000000000000
  R10: 0000000000000000 R11: ffffffff83619b90 R12: ffff923fa9540000
  R13: 0000000000080007 R14: ffff923f6d35d000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff929d0d7c0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffe38687000000 CR3: 0000005224c34005 CR4: 0000000000770ee0
  PKRU: 55555554
  Call Trace:
   <TASK>
   sev_free_vcpu+0xcb/0x110 [kvm_amd]
   svm_vcpu_free+0x75/0xf0 [kvm_amd]
   kvm_arch_vcpu_destroy+0x36/0x140 [kvm]
   kvm_destroy_vcpus+0x67/0x100 [kvm]
   kvm_arch_destroy_vm+0x161/0x1d0 [kvm]
   kvm_put_kvm+0x276/0x560 [kvm]
   kvm_vm_release+0x25/0x30 [kvm]
   __fput+0x106/0x280
   ____fput+0x12/0x20
   task_work_run+0x86/0xb0
   do_exit+0x2e3/0x9c0
   do_group_exit+0xb1/0xc0
   __x64_sys_exit_group+0x1b/0x20
   do_syscall_64+0x41/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   </TASK>
  CR2: ffffe38687000000

The Linux kernel CVE team has assigned CVE-2023-54296 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.19 with commit 6defa24d3b12bbd418bc8526dea1cbc605265c06 and fixed in 6.1.54 with commit 5c18ace750e4d4d58d7da02d1c669bf21c824158
	Issue introduced in 5.19 with commit 6defa24d3b12bbd418bc8526dea1cbc605265c06 and fixed in 6.5.4 with commit 2ee4b180d51b12a45bdd3264629719ef6a572a73
	Issue introduced in 5.19 with commit 6defa24d3b12bbd418bc8526dea1cbc605265c06 and fixed in 6.6 with commit f1187ef24eb8f36e8ad8106d22615ceddeea6097
	Issue introduced in 5.18.8 with commit 229334a8b1d0d5e60d3bdd091bbc4552d5321c97

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-54296
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	arch/x86/kvm/svm/sev.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/5c18ace750e4d4d58d7da02d1c669bf21c824158
	https://git.kernel.org/stable/c/2ee4b180d51b12a45bdd3264629719ef6a572a73
	https://git.kernel.org/stable/c/f1187ef24eb8f36e8ad8106d22615ceddeea6097