GHSA-FPRR-Q2H8-XVJ4

Vulnerability from github – Published: 2026-05-01 15:30 – Updated: 2026-05-03 09:33
VLAI?
Details

In the Linux kernel, the following vulnerability has been resolved:

net/x25: Fix potential double free of skb

When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain:

x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again

This would free the same skb twice. Looking at x25_backlog_rcv:

net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }

Severity ?
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2026-43011"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-01T15:16:44Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/x25: Fix potential double free of skb\n\nWhen alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at\nline 48 and returns 1 (error).\nThis error propagates back through the call chain:\n\nx25_queue_rx_frame returns 1\n    |\n    v\nx25_state3_machine receives the return value 1 and takes the else\nbranch at line 278, setting queued=0 and returning 0\n    |\n    v\nx25_process_rx_frame returns queued=0\n    |\n    v\nx25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb)\nagain\n\nThis would free the same skb twice. Looking at x25_backlog_rcv:\n\nnet/x25/x25_in.c:x25_backlog_rcv() {\n    ...\n    queued = x25_process_rx_frame(sk, skb);\n    ...\n    if (!queued)\n        kfree_skb(skb);\n}",
  "id": "GHSA-fprr-q2h8-xvj4",
  "modified": "2026-05-03T09:33:10Z",
  "published": "2026-05-01T15:30:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43011"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3f5e3005984645bf5bd129c6b13149879580b1fb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/524371398d8463ea7e101fce2cbf3915645d1730"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c87dd137c0dad07cc55f98181ff380b0c23d2878"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d10a26aa4d072320530e6968ef945c8c575edf61"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f782dd382203b2a8c4552a628431b7de65a19a7b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fa1dbc93530b34fab0da9862426fe9c918c74dc0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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