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CVE-2026-46207

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix empty payload in tap skb for non-linear buffers For non-linear skbs, virtio_transport_build_skb() goes through virtio_transport_copy_nonlinear_skb() to copy the original payload in the new skb to be delivered to the vsockmon tap device. This manually initializes an iov_iter but does not set iov_iter.count. Since the iov_iter is zero-initialized, the copy length is zero and no payload is actually copied to the monitor interface, leaving data un-initialized. Fix this by removing the linear vs non-linear split and using skb_copy_datagram_iter() with iov_iter_kvec() for all cases, as vhost-vsock already does. This handles both linear and non-linear skbs, properly initializes the iov_iter, and removes the now unused virtio_transport_copy_nonlinear_skb(). While touching this code, let's also check the return value of skb_copy_datagram_iter(), even though it's unlikely to fail.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-28 10:16:36.340000
Last modified
2026-11-06 17:17:44.420000
View original CVE JSON 
{
  "id": "CVE-2026-46207",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-28T10:16:36.340",
  "lastModified": "2026-11-06T17:17:44.420",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: fix empty payload in tap skb for non-linear buffers\n\nFor non-linear skbs, virtio_transport_build_skb() goes through\nvirtio_transport_copy_nonlinear_skb() to copy the original payload\nin the new skb to be delivered to the vsockmon tap device.\nThis manually initializes an iov_iter but does not set iov_iter.count.\nSince the iov_iter is zero-initialized, the copy length is zero and no\npayload is actually copied to the monitor interface, leaving data\nun-initialized.\n\nFix this by removing the linear vs non-linear split and using\nskb_copy_datagram_iter() with iov_iter_kvec() for all cases, as\nvhost-vsock already does. This handles both linear and non-linear skbs,\nproperly initializes the iov_iter, and removes the now unused\nvirtio_transport_copy_nonlinear_skb().\n\nWhile touching this code, let's also check the return value of\nskb_copy_datagram_iter(), even though it's unlikely to fail."
    }
  ],
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      "affectedData": [
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          "product": "Linux",
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              "versionType": "original_commit_for_fix",
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  ],
  "metrics": {
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          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
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        "exploitabilityScore": 1.8,
        "impactScore": 3.6
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}