CVE-2022-48765

2024-06-2012:15:14

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

kvm

preemption timer

6.5 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.7%

JSON

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

KVM: LAPIC: Also cancel preemption timer during SET_LAPIC

The below warning is splatting during guest reboot.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]
CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G I 5.17.0-rc1+ #5
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]
Call Trace:
<TASK>
kvm_vcpu_ioctl+0x279/0x710 [kvm]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd39797350b

This can be triggered by not exposing tsc-deadline mode and doing a reboot in
the guest. The lapic_shutdown() function which is called in sys_reboot path
will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears
APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode
switch between tsc-deadline and oneshot/periodic, which can result in preemption
timer be cancelled in apic_update_lvtt(). However, We can’t depend on this when
not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption
timer. Qemu will synchronise states around reset, let’s cancel preemption timer
under KVM_SET_LAPIC.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.15.0–5.15.19

linuxlinux_kernelRange5.16.0–5.16.5

linuxlinux_kernelRange5.17.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/kvm/lapic.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "54b3439c8e70",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "ce55f63f6cea",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "35fe7cfbab2e",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/kvm/lapic.c"
    ],
    "versions": [
      {
        "version": "5.15.19",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16.5",
        "lessThanOrEqual": "5.16.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.17",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]