A vulnerability was found in btrfs_alloc_tree_b in fs/btrfs/extent-tree.c in the Linux…
Priority LOW 25CWE-667Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- 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. Impact type from CWE-667 and the CVSS impact.
Summary
A vulnerability was found in btrfs_alloc_tree_b in fs/btrfs/extent-tree.c in the Linux kernel due to an improper lock operation in btrfs. In this flaw, a user with a local privilege may cause a denial of service (DOS) due to a deadlock problem.
Why it matters now
EPSS 0.004 34th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | kernel | kernel 5.15 rc6 | — | No fix listed | CNA |
- kernel Vendor— Affected kernel 5.15 rc6 Fixed in — No fix listed CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.15 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:-:*:*:*:*:*:* | 5.15 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* | 5.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* | 5.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* | 5.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* | 5.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* | 5.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.15 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:-:*:*:*:*:*:* Versions 5.15 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* Versions 5.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* Versions 5.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* Versions 5.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* Versions 5.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* Versions 5.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-4149
- 2026-10-03 Alias added: GHSA-j26f-m94f-4hr4
References
Sources
- CVE-2021-4149 · CVE Program
- CVE-2021-4149 · NVD
- FIRST EPSS
- GHSA-j26f-m94f-4hr4 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-4149 · Red Hat security data · CC BY 4.0
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