CVE-2021-47111

2024-03-1521:15:06

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

web.nvd.nist.gov

linux kernel

xen-netback

reference taking

use-after-free

xsa-374

cve-2021-28691

7.4 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.7%

JSON

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

xen-netback: take a reference to the RX task thread

Do this in order to prevent the task from being freed if the thread
returns (which can be triggered by the frontend) before the call to
kthread_stop done as part of the backend tear down. Not taking the
reference will lead to a use-after-free in that scenario. Such
reference was taken before but dropped as part of the rework done in
2ac061ce97f4.

Reintroduce the reference taking and add a comment this time
explaining why it’s needed.

This is XSA-374 / CVE-2021-28691.