NULL pointer dereference in Linux

CVE-2022-49568

In the Linux kernel, the following vulnerability has been resolved: KVM: Don't null dereference ops->destroy A KVM device cleanup happens in either of two callbacks: 1) destroy() which is called when the VM is being destroyed; 2) release() which is called when a device fd is closed. Most KVM devices use 1) but Book3s's interrupt controller KVM devices (XICS, XIVE, XIVE-native) use 2) as they need to close and reopen during the machine execution. The error handling in kvm_ioctl_create_device() assumes destroy() is always defined which leads to NULL dereference as discovered by Syzkaller. This adds a checks for destroy!=NULL and adds a missing release(). This is not changing kvm_destroy_devices() as devices with defined release() should have been removed from the KVM devices list by then.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (20.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2022-49568: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

  • Linux — versions 852b6d57dc7fa378019786fa84727036e56839ea, 3.10, 0
  • Linux Kernel — versions 5.19

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2022-49568?
CVE-2022-49568 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2025-02-26.
How severe is CVE-2022-49568?
Medium severity. CVSS v3 base score is 5.5 out of 10.