CVE-2025-21904 caif_virtio: fix wrong pointer check in cfv_probe()

What is CVE-2025-21904?

CVE-2025-21904 is a medium-severity vulnerability in Linux kernel, published on 1 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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().

Weakness: CWE-476

Which versions are affected by CVE-2025-21904?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21904?

Apply the vendor's patch.

Is CVE-2025-21904 being exploited?

There is no known exploitation of CVE-2025-21904 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-60346, AZL-60363, BELL-CVE-2025-21904, DEBIAN-CVE-2025-21904, GHSA-x97h-4pwx-3c9h, ROOT-OS-UBUNTU-2404-CVE-2025-21904 and 1 more.