NULL pointer dereference in Linux

CVE-2025-21904

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().

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (12.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21904: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Linux — versions 0d2e1a2926b1839a4b74519e660739b2566c9386, 3.10, 0
  • Linux Kernel — versions 6.14

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21904?
CVE-2025-21904 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2025-04-01.
How severe is CVE-2025-21904?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2025-21904 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.