vsock: prevent null-ptr-deref in vsock_*[has_data|has_space]
In the Linux kernel, the following vulnerability has been resolved: vsock: prevent null-ptr-deref in vsock_*[has_data|has_space] Recent reports have shown how we sometimes call vsock_*_has_data() when a vsock socket has been de-assigned from a transport (see attached links), but we shouldn't. Previous commits should have solved the real problems, but we may have more in the future, so to avoid null-ptr-deref, we can return 0 (no space, no data available) but with a warning. This way the code should continue to run in a nearly consistent state and have a warning that allows us to debug future problems.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 5.10.234, 5.15.177, 6.1.127, 6.12.11, 6.6.74
- CVEs
- CVE-2025-21666
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 2 Nov 2026, 20:29 UTC · Revision 1
Source evidence
vsock: prevent null-ptr-deref in vsock_*[has_data|has_space]
core-osv · Original sourcePublished 31 Jan 2025, 11:25 UTC
In the Linux kernel, the following vulnerability has been resolved: vsock: prevent null-ptr-deref in vsock_*[has_data|has_space] Recent reports have shown how we sometimes call vsock_*_has_data() when a vsock socket has been de-assigned from a transport (see attached links), but we shouldn't. Previous commits should have solved the real problems, but we may have more in the future, so to avoid null-ptr-deref, we can return 0 (no space, no data available) but with a warning. This way the code should continue to run in a nearly consistent state and have a warning that allows us to debug future problems.
osv:CVE-2025-21666
Kernel
Fixed versions: 5.10.234, 5.15.177, 6.1.127, 6.6.74, 6.12.11
Complete source record
{
"id": "6da4f4d6ae928e0ed4793d5e7c263b7519afe8e0cd2ed4c4d61c8a50acc1e02b",
"url": "https://osv.dev/vulnerability/CVE-2025-21666",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "vsock: prevent null-ptr-deref in vsock_*[has_data|has_space]",
"summary": "In the Linux kernel, the following vulnerability has been resolved: vsock: prevent null-ptr-deref in vsock_*[has_data|has_space] Recent reports have shown how we sometimes call vsock_*_has_data() when a vsock socket has been de-assigned from a transport (see attached links), but we shouldn't. Previous commits should have solved the real problems, but we may have more in the future, so to avoid null-ptr-deref, we can return 0 (no space, no data available) but with a warning. This way the code should continue to run in a nearly consistent state and have a warning that allows us to debug future problems.",
"evidence": "osv:CVE-2025-21666",
"products": [
{
"name": {
"value": "Kernel",
"evidence": "/affected/1/package/name"
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"prerequisites": [],
"fixed_versions": [
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"value": "5.10.234",
"evidence": "/affected/1/ranges"
},
{
"value": "5.15.177",
"evidence": "/affected/1/ranges"
},
{
"value": "6.1.127",
"evidence": "/affected/1/ranges"
},
{
"value": "6.6.74",
"evidence": "/affected/1/ranges"
},
{
"value": "6.12.11",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "CVE-2025-21666",
"aliases": [
"CVE-2025-21666"
],
"metrics": [
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
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"affected": [
{
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"type": "GIT",
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{
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{
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{
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{
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{
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{
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"events": [
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"introduced": "6.2.0"
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{
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{
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"events": [
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{
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],
"package": {
"name": "Kernel",
"ecosystem": "Linux"
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"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21666.json"
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],
"modified": "2026-10-28T02:30:23.818089139Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-265688.html",
"https://git.kernel.org/stable/c/91751e248256efc111e52e15115840c35d85abaf",
"https://git.kernel.org/stable/c/9e5fed46ccd2c34c5fa5a9c8825ce4823fdc853e",
"https://git.kernel.org/stable/c/b52e50dd4fabd12944172bd486a4f4853b7f74dd",
"https://git.kernel.org/stable/c/bc9c49341f9728c31fe248c5fbba32d2e81a092b",
"https://git.kernel.org/stable/c/c23d1d4f8efefb72258e9cedce29de10d057f8ca",
"https://git.kernel.org/stable/c/daeac89cdb03d30028186f5ff7dc26ec8fa843e7",
"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html",
"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21666.json",
"https://nvd.nist.gov/vuln/detail/CVE-2025-21666",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21666.json"
}
},
"related_cves": [
{
"value": "CVE-2025-21666",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 489860,
"published_at": "2025-01-31T11:25:31.138+00:00"
}