CVE-2025-21904
MediumIn 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().
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-476CVE-2025-21904 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
3.10
and later are affected. Fixed in
5.4.291,
5.10.235,
5.15.179,
6.1.131,
6.6.83,
6.12.19,
6.13.7,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21904 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/29e0cd296c87240278e2f7ea4cf3f496b60c03af
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PatchKernel patch commithttps://git.kernel.org/stable/c/56cddf71cce3b15b078e937fadab29962b6f6643
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PatchKernel patch commithttps://git.kernel.org/stable/c/597c27e5f04cb50e56cc9aeda75d3e42b6b89c3e
Frequently asked questions
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What is CVE-2025-21904?
CVE-2025-21904 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 3.10 onward and has been patched in 5.4.291, 5.10.235, 5.15.179 and others. CVE-2025-21904 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-21904?
CVE-2025-21904 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-21904?
Yes — CVE-2025-21904 has been patched. Fixed versions include 5.4.291, 5.10.235, 5.15.179 and others. If you are running Linux kernel 3.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21904 actively exploited?
No — CVE-2025-21904 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is NULL Pointer Dereference (CWE-476)?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →