Race condition in the tty_fasync function in drivers/char/tty_io.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
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
Race condition in the tty_fasync function in drivers/char/tty_io.c in the Linux kernel before 2.6.32.6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via unknown vectors, related to the put_tty_queue and __f_setown functions. NOTE: the vulnerability was addressed in a different way in 2.6.32.9.
Why it matters now
EPSS 0.00263 18th percentileScored 2026-11-07
Fix Fixed Red Hat: 1 advisory
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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 2.6.32.6 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:5.0:*:*:*:*:*:*:* | 5.0 | Vulnerable | Debian |
| cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:*:*:*:* | 6.06 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:-:*:*:* | 8.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:9.04:*:*:*:*:*:*:* | 9.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:9.10:*:*:*:*:*:*:* | 9.10 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:* | 10.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:10.10:*:*:*:*:*:*:* | 10.10 | Vulnerable | Canonical |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 2.6.32.6 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:5.0:*:*:*:*:*:*:* Versions 5.0 Vulnerable ·Debian
- cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:*:*:*:* Versions 6.06 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:-:*:*:* Versions 8.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:9.04:*:*:*:*:*:*:* Versions 9.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:9.10:*:*:*:*:*:*:* Versions 9.10 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:* Versions 10.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:10.10:*:*:*:*:*:*:* Versions 10.10 Vulnerable ·Canonical
Remediation
Red Hat 1 advisory
- RHSA-2010:0161 Released 2010-03-23 · Red Hat rating Importantkernel-rt security and bug fix update
- MRG Realtime for RHEL 5 Server kernel-rt-2.6.24.7-149.el5rt, kernel-rt-debug-2.6.24.7-149.el5rt, kernel-rt-debug-devel-2.6.24.7-149.el5rt +6
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| MRG Realtime for RHEL 5 Server | Fixed | RHSA-2010:0161 |
Timeline
- 2026-10-02 Threatist record created from CVE-2009-4895
- 2026-10-03 Alias added: GHSA-cjgr-h69p-cj83
References
Patch 2
Advisory 6
- [oss-security] 20100615 Re: CVE Request - kernel: put_tty_queue NULL pointer deref
- USN-1000-1
- [oss-security] 20100615 Re: CVE Request - kernel: put_tty_queue NULL pointer deref
- [oss-security] 20100615 Re: CVE Request - kernel: put_tty_queue NULL pointer deref
- https://bugzilla.redhat.com/show_bug.cgi?id=559100
- DSA-2094
Sources
- CVE-2009-4895 · CVE Program
- CVE-2009-4895 · NVD
- FIRST EPSS
- GHSA-cjgr-h69p-cj83 · GitHub Advisory Database · CC BY 4.0
- CVE-2009-4895 · Red Hat security data · CC BY 4.0
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