A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.
Created xen tracking bugs for this issue:
Affects: fedora-all [bug 1970537]
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1971599]
This was fixed for Fedora with the 5.12.10 stable kernel updates.