CVE-2021-28964 Race condition in n/a

What is CVE-2021-28964?

CVE-2021-28964 is a medium-severity vulnerability in Debian Debian Linux, published on 22 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

Weakness: CWE-362

Which versions are affected by CVE-2021-28964?

It affects 7 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Aff A250 Firmware, Netapp Cloud Backup, Netapp Fas 500f Firmware and 1 more.

How do I fix CVE-2021-28964?

Apply the vendor's patch.

Is CVE-2021-28964 being exploited?

There is no known exploitation of CVE-2021-28964 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-6541, DEBIAN-CVE-2021-28964, GHSA-rrj4-3rqr-76cq, UBUNTU-CVE-2021-28964.