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net: gro: don't merge zcopy skbs

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.

Products
Kernel
Affected versions
Not specified
Fixed versions
6.1.176, 6.12.92, 6.18.34, 6.6.142, 7.0.11
CVEs
CVE-2026-46323
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 01:33 UTC · Revision 1

Source evidence

net: gro: don't merge zcopy skbs

core-osv · Original source

Published 9 Jun 2026, 12:11 UTC

In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.

osv:CVE-2026-46323

Kernel

Fixed versions: 6.1.176, 6.6.142, 6.12.92, 6.18.34, 7.0.11

Complete source record
{
  "id": "a9e818d32d9dbd4204e7c6a932cb175e5f9c14e39adc8d037e4b17e223a4afe4",
  "url": "https://osv.dev/vulnerability/CVE-2026-46323",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: gro: don't merge zcopy skbs",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.",
    "evidence": "osv:CVE-2026-46323",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.176",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.142",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.92",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.34",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.11",
            "evidence": "/affected/1/ranges"
          }
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        "affected_versions": []
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    "severity": "high",
    "structured": {
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      "aliases": [
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      "metrics": [
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          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
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                {
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                {
                  "fixed": "e334cbf3388fd9334503a778a82d9e9f14dd2f71"
                },
                {
                  "fixed": "44bea2032af0425e4ce6d26a8af0ede79db49ec1"
                },
                {
                  "fixed": "4db79a322db8c97f7b73b8a347395ef4d685eb40"
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              ]
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46323.json"
          }
        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
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            {
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                  "introduced": "6.2.0"
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            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.92"
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            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.34"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46323.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:41.204211363Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-784472.html",
        "https://git.kernel.org/stable/c/1f9c828556416fbe3f49386708ce999fc4d4da06",
        "https://git.kernel.org/stable/c/3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d",
        "https://git.kernel.org/stable/c/44bea2032af0425e4ce6d26a8af0ede79db49ec1",
        "https://git.kernel.org/stable/c/479084ae0e1d9cb7929cb4298d35623de189f80a",
        "https://git.kernel.org/stable/c/4db79a322db8c97f7b73b8a347395ef4d685eb40",
        "https://git.kernel.org/stable/c/e334cbf3388fd9334503a778a82d9e9f14dd2f71",
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46323.json",
        "https://access.redhat.com/errata/RHSA-2026:27708",
        "https://access.redhat.com/errata/RHSA-2026:27731",
        "https://access.redhat.com/errata/RHSA-2026:27735",
        "https://access.redhat.com/errata/RHSA-2026:36018",
        "https://access.redhat.com/errata/RHSA-2026:44230",
        "https://access.redhat.com/errata/RHSA-2026:44231",
        "https://access.redhat.com/errata/RHSA-2026:44259",
        "https://access.redhat.com/errata/RHSA-2026:44262",
        "https://access.redhat.com/errata/RHSA-2026:44270",
        "https://access.redhat.com/errata/RHSA-2026:47727",
        "https://access.redhat.com/errata/RHSA-2026:62639",
        "https://access.redhat.com/errata/RHSA-2026:62640",
        "https://access.redhat.com/errata/RHSA-2026:62641",
        "https://access.redhat.com/errata/RHSA-2026:62642",
        "https://access.redhat.com/security/cve/CVE-2026-46323",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46323.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-46323",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2479832",
        "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/2026/46xxx/CVE-2026-46323.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-46323",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509116,
  "published_at": "2026-06-09T12:11:15.562+00:00"
}