CVE-2021-28964: Debian Linux

Medium severity, CVSS 4.7. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Debian Debian Linux: version 9.0 only
• Fedoraproject Fedora: version 32 only; version 33 only; version 34 only
• Linux Linux Kernel: up to and including 5.11.8
• Netapp Aff a250 Firmware: affected versions not specified
• Netapp Cloud Backup: affected versions not specified
• Netapp Fas 500f Firmware: affected versions not specified
• Netapp Solidfire Baseboard Management Controller Firmware: affected versions not specified

Published 2021-03-22. Last modified 2026-06-17.