USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()
Priority LOW 24CWE-476Published · 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
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb() This patch addresses a null-ptr-deref in qt2_process_read_urb() due to an incorrect bounds check in the following: if (newport > serial->num_ports) { dev_err(&port->dev, "%s - port change to invalid port: %i\n", __func__, newport); break; } The condition doesn't account for the valid range of the serial->port buffer, which is from 0 to serial->num_ports - 1. When newport is equal to serial->num_ports, the assignment of "port" in the following code is out-of-bounds and NULL: serial_priv->current_port = newport; port = serial->port[serial_priv->current_port]; The fix checks if newport is greater than or equal to serial->num_ports indicating it is out-of-bounds.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00226 13th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.290, 5.10.234, 5.15.178 +5Red Hat: 1 advisoryRed Hat: 5 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.5 and later | 5.4.290, 5.10.234, 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1, 6.14 | Patch available | CNA |
- Linux VendorLinux Affected 3.5 and later Fixed in 5.4.290, 5.10.234, 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1, 6.14 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.5 to before 5.4.290; 5.5 to before 5.10.234; 5.11 to before 5.15.178; 5.16 to before 6.1.128; 6.2 to before 6.6.75; 6.7 to before 6.12.12 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:* | 6.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* | 6.13 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* | 6.13 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* | 6.13 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* | 6.13 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* | 6.13 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* | 6.13 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:* | 6.13 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.5 to before 5.4.290; 5.5 to before 5.10.234; 5.11 to before 5.15.178; 5.16 to before 6.1.128; 6.2 to before 6.6.75; 6.7 to before 6.12.12 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:* Versions 6.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* Versions 6.13 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* Versions 6.13 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* Versions 6.13 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* Versions 6.13 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* Versions 6.13 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* Versions 6.13 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:* Versions 6.13 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.290, 5.10.234, 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1, 6.14
Red Hat 1 advisory
- RHSA-2025:6966 Released 2025-05-13 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.12.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.12.1.el9_6, kernel-64k-devel-5.14.0-570.12.1.el9_6 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.12.1.el9_6, kernel-64k-5.14.0-570.12.1.el9_6, kernel-64k-core-5.14.0-570.12.1.el9_6 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.12.1.el9_6, libperf-5.14.0-570.12.1.el9_6
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-64k-5.14.0-570.12.1.el9_6, kernel-rt-64k-core-5.14.0-570.12.1.el9_6 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-core-5.14.0-570.12.1.el9_6, kernel-rt-debug-5.14.0-570.12.1.el9_6 +11
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 |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:6966 |
Not affected: 1 product
- Red Hat Enterprise Linux 10
Timeline
- 2026-10-02 Threatist record created from CVE-2025-21689
- 2026-10-03 Alias added: GHSA-mgqg-wqxj-q43c
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/fa4c7472469d97c4707698b4c0e098f8cfc2bf22
- https://git.kernel.org/stable/c/94770cf7c5124f0268d481886829dc2beecc4507
- https://git.kernel.org/stable/c/6068dcff7f19e9fa6fa23ee03453ad6a40fa4efe
- https://git.kernel.org/stable/c/4b9b41fabcd38990f69ef0cee9c631d954a2b530
- https://git.kernel.org/stable/c/6377838560c03b36e1153a42ef727533def9b68f
- https://git.kernel.org/stable/c/f371471708c7d997f763b0e70565026eb67cc470
- https://git.kernel.org/stable/c/8542b33622571f54dfc2a267fce378b6e3840b8b
- https://git.kernel.org/stable/c/575a5adf48b06a2980c9eeffedf699ed5534fade
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-21689 · CVE Program
- CVE-2025-21689 · NVD
- FIRST EPSS
- GHSA-mgqg-wqxj-q43c · GitHub Advisory Database · CC BY 4.0
- CVE-2025-21689 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences