A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. This flaw affects kernel versions prior to 5.15 rc7.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-4032
• https://bugzilla.redhat.com/show_bug.cgi?id=2027403
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f7d8a19f9a056a05c5c509fa65af472a322abfee
• https://lkml.org/lkml/2021/9/8/587