Linux Kernel up to 6.13.6 caif_virtio cfv_probe null pointer dereference

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5.5	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.13.6. This affects the function cfv_probe of the component caif_virtio. The manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2025-21904. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.13.6. Affected is the function cfv_probe of the component caif_virtio. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: caif_virtio: fix wrong pointer check in cfv_probe() del_vqs() frees virtqueues, therefore cfv->vq_tx pointer should be checked for NULL before calling it, not cfv->vdev. Also the current implementation is redundant because the pointer cfv->vdev is dereferenced before it is checked for NULL. Fix this by checking cfv->vq_tx for NULL instead of cfv->vdev before calling del_vqs().

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2025-21904 since 12/29/2024. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 234309 (Debian dsa-5900 : affs-modules-6.1.0-28-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.291, 5.10.235, 5.15.179, 6.1.131, 6.6.83, 6.12.19 or 6.13.7 eliminates this vulnerability. Applying the patch 990fff6980d0c1693d60a812f58dbf93eab0473f/7b5fe58959822e6cfa884327cabba6be3b01883d/8e4e08ca4cc634b337bb74bc9a70758fdeda0bcb/29e0cd296c87240278e2f7ea4cf3f496b60c03af/90d302619ee7ce5ed0c69c29c290bdccfde66418/56cddf71cce3b15b078e937fadab29962b6f6643/597c27e5f04cb50e56cc9aeda75d3e42b6b89c3e/a466fd7e9fafd975949e5945e2f70c33a94b1a70 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (234309) and CERT Bund (WID-SEC-2025-0683). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• SolarWinds Security Event Manager
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM Security Verify Access

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.290
• 5.10.234
• 5.15.178
• 6.1.130
• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.6.60
• 6.6.61
• 6.6.62
• 6.6.63
• 6.6.64
• 6.6.65
• 6.6.66
• 6.6.67
• 6.6.68
• 6.6.69
• 6.6.70
• 6.6.71
• 6.6.72
• 6.6.73
• 6.6.74
• 6.6.75
• 6.6.76
• 6.6.77
• 6.6.78
• 6.6.79
• 6.6.80
• 6.6.81
• 6.6.82
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.13.0
• 6.13.1
• 6.13.2
• 6.13.3
• 6.13.4
• 6.13.5
• 6.13.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
• 🔍
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CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 234309
Nessus Name: Debian dsa-5900 : affs-modules-6.1.0-28-4kc-malta-di - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.4.291/5.10.235/5.15.179/6.1.131/6.6.83/6.12.19/6.13.7
Patch: 990fff6980d0c1693d60a812f58dbf93eab0473f/7b5fe58959822e6cfa884327cabba6be3b01883d/8e4e08ca4cc634b337bb74bc9a70758fdeda0bcb/29e0cd296c87240278e2f7ea4cf3f496b60c03af/90d302619ee7ce5ed0c69c29c290bdccfde66418/56cddf71cce3b15b078e937fadab29962b6f6643/597c27e5f04cb50e56cc9aeda75d3e42b6b89c3e/a466fd7e9fafd975949e5945e2f70c33a94b1a70

Timelineinfo

12/29/2024 🔍
04/01/2025 +92 days 🔍
04/01/2025 +0 days 🔍
02/01/2026 +306 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-21904 (🔍)
GCVE (CVE): GCVE-0-2025-21904
GCVE (VulDB): GCVE-100-302634
CERT Bund: WID-SEC-2025-0683 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 04/01/2025 19:03
Updated: 02/01/2026 05:04
Changes: 04/01/2025 19:03 (59), 04/14/2025 11:59 (2), 07/20/2025 00:15 (7), 07/21/2025 18:29 (1), 10/26/2025 15:44 (1), 02/01/2026 05:04 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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