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TI-2021-09889 Aliases CVE-2021-28964GHSA-rrj4-3rqr-76cq

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel…

Priority LOW 21CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Will not fix Red Hat: no fix planned

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

EPSS 0.00267 18th percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 11

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*up to 5.11.8VulnerableLinux
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*32VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:o:netapp:aff_a250_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:aff_a250:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:fas_500f_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions up to 5.11.8 Vulnerable ·Linux
  • cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:o:netapp:aff_a250_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:aff_a250:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:fas_500f_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
Show 1 more CPE
CPEVersionsRoleVendor
cpe:2.3:h:netapp:fas_500f:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
  • cpe:2.3:h:netapp:fas_500f:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Not affected: 3 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-28964
  2. 2026-10-03 Alias added: GHSA-rrj4-3rqr-76cq

References

Advisory 7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences