CVE-2022-49568

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux852b6d57dc7fa378019786fa84727036e56839ea < 170465715a60cbb7876e6b961b21bd3225469da8affected
LinuxLinux852b6d57dc7fa378019786fa84727036e56839ea < 3616776bc51cd3262bb1be60cc01c72e0a1959cfaffected
LinuxLinux852b6d57dc7fa378019786fa84727036e56839ea < e91665fbbf3ccb268b268a7d71a6513538d813acaffected
LinuxLinux852b6d57dc7fa378019786fa84727036e56839ea < d4a5a79b780891c5cbdfdc6124d46fdf8d13dba1affected
LinuxLinux852b6d57dc7fa378019786fa84727036e56839ea < e8bc2427018826e02add7b0ed0fc625a60390ae5affected
LinuxLinux3.10affected
LinuxLinux0 < 3.10unaffected
LinuxLinux5.4.210 <= 5.4.*unaffected
LinuxLinux5.10.134 <= 5.10.*unaffected
LinuxLinux5.15.58 <= 5.15.*unaffected
LinuxLinux5.18.15 <= 5.18.*unaffected
LinuxLinux5.19 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References