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Vulnerability record · CVE-2021-28964 · published 22 March 2021

CVE-2021-28964: Linux kernel race condition vulnerability

Linux · Linux Kernel

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.

4.7 CVSS 3.1 Medium EPSS 0.27% · top 83.1% CWE-362 · Race condition
4.7CVSS 3.1 base score, v2 1.9
0.27%EPSS exploitation probability, 30 days
NoNot in CISA KEV
7Affected product versions listed by NVD
14References
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

7 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbcc7d57bffc0c8cac9dac11bec548597d59a6a5 Mailing ListVendor Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4VCKIOXCOZGXBEZMO5LGGV5
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PTRNPQTZ4GVS46SZ4OBXY5Y
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUA
https://security.netapp.com/advisory/ntap-20210430-0003/ Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbcc7d57bffc0c8cac9dac11bec548597d59a6a5 Mailing ListVendor Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4VCKIOXCOZGXBEZMO5LGGV5
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PTRNPQTZ4GVS46SZ4OBXY5Y
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUA
https://security.netapp.com/advisory/ntap-20210430-0003/ Third Party Advisory

Track CVE-2021-28964 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

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Source: NIST National Vulnerability Database (record CVE-2021-28964), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.