GHSA-PX64-7MQ2-M5MM

Vulnerability from github – Published: 2026-09-16 12:30 – Updated: 2026-09-16 15:31
VLAI
Details

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

net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()

skb_zerocopy() copies frags from @from into @to. On an skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive operation on the source skb the copy helper does not own. That completes @from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the SKBFL_SHARED_FRAG page-ownership marker.

Both callers already report the failure on their own drop path. nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by dropping it here.

On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on this error: do_execute_actions() ignores output_userspace()'s return value and, unless the upcall was the last action, keeps forwarding the same skb through the flow's remaining actions. The uarg is completed while that skb is still in flight, telling the producer its buffers are free, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack still handles. That flag is what makes esp_input() call skb_cow_data() instead of decrypting in place, so a later local ESP delivery can decrypt over frags the skb does not own privately.

Leave error reporting to the callers.

Severity
9.3 (Critical)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2026-90049"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T11:17:18Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: don\u0027t skb_tx_error() the source skb in skb_zerocopy()\n\nskb_zerocopy() copies frags from @from into @to. On an\nskb_orphan_frags() failure it calls skb_tx_error(@from), a destructive\noperation on the source skb the copy helper does not own. That completes\n@from\u0027s zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the\nSKBFL_SHARED_FRAG page-ownership marker.\n\nBoth callers already report the failure on their own drop path.\nnfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in\nthe flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by\ndropping it here.\n\nOn Open vSwitch\u0027s OVS_ACTION_ATTR_USERSPACE path the skb is not freed on\nthis error: do_execute_actions() ignores output_userspace()\u0027s return\nvalue and, unless the upcall was the last action, keeps forwarding the\nsame skb through the flow\u0027s remaining actions. The uarg is completed\nwhile that skb is still in flight, telling the producer its buffers are\nfree, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack\nstill handles. That flag is what makes esp_input() call skb_cow_data()\ninstead of decrypting in place, so a later local ESP delivery can\ndecrypt over frags the skb does not own privately.\n\nLeave error reporting to the callers.",
  "id": "GHSA-px64-7mq2-m5mm",
  "modified": "2026-09-16T15:31:09Z",
  "published": "2026-09-16T12:30:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90049"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/04dd250a78e268af3e7124beb1dc10ec1dd88d60"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/767ec2a65cc022d303b0c9c12811e7db22057341"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8069643ae64dfdf634b6c78c7f622e5323031436"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/849bdb83123760a865bcb2970127f4c0b9423ba3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8ece906150128d5ec2462aabcc978c568433eca4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a13b1e80e5015cd732440b475c0ef443dc4a2157"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bab5a851e44a3601d31f2aa8043f385bb50ac5d9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fb10e0e9b220a2eed08931a60dbaad9a2370c908"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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