{
  "threat_severity" : "Moderate",
  "public_date" : "2025-04-01T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net: gso: fix ownership in __udp_gso_segment",
    "id" : "2356587",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2356587"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.0",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnet: gso: fix ownership in __udp_gso_segment\nIn __udp_gso_segment the skb destructor is removed before segmenting the\nskb but the socket reference is kept as-is. This is an issue if the\noriginal skb is later orphaned as we can hit the following bug:\nkernel BUG at ./include/linux/skbuff.h:3312!  (skb_orphan)\nRIP: 0010:ip_rcv_core+0x8b2/0xca0\nCall Trace:\nip_rcv+0xab/0x6e0\n__netif_receive_skb_one_core+0x168/0x1b0\nprocess_backlog+0x384/0x1100\n__napi_poll.constprop.0+0xa1/0x370\nnet_rx_action+0x925/0xe50\nThe above can happen following a sequence of events when using\nOpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an\nOVS_ACTION_ATTR_OUTPUT action:\n1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb\ngoes through queue_gso_packets and then __udp_gso_segment, where its\ndestructor is removed.\n2. The segments' data are copied and sent to userspace.\n3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the\nsame original skb is sent to its path.\n4. If it later hits skb_orphan, we hit the bug.\nFix this by also removing the reference to the socket in\n__udp_gso_segment." ],
  "statement" : "If UDP fragmentation offload being used (that allows a device to fragment an oversized UDP datagram into multiple IPv fragments), then this bug could happen. The bug happens when skb_orphan function later being called. It is complex to trigger the bug (few conditions should happen simultaneously) and only local user can trigger it.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-06-09T00:00:00Z",
    "advisory" : "RHSA-2025:8669",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.0",
    "package" : "kernel-0:6.12.0-55.16.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-06-09T00:00:00Z",
    "advisory" : "RHSA-2025:8643",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.21.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-06-09T00:00:00Z",
    "advisory" : "RHSA-2025:8643",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.21.1.el9_6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-21926\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-21926\nhttps://lore.kernel.org/linux-cve-announce/2025040132-CVE-2025-21926-fd40@gregkh/T" ],
  "name" : "CVE-2025-21926",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}