{
  "threat_severity" : "Moderate",
  "public_date" : "2026-03-18T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net: add proper RCU protection to /proc/net/ptype",
    "id" : "2448703",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2448703"
  },
  "cvss3" : {
    "cvss3_base_score" : "4.7",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-362",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnet: add proper RCU protection to /proc/net/ptype\nYin Fengwei reported an RCU stall in ptype_seq_show() and provided\na patch.\nReal issue is that ptype_seq_next() and ptype_seq_show() violate\nRCU rules.\nptype_seq_show() runs under rcu_read_lock(), and reads pt->dev\nto get device name without any barrier.\nAt the same time, concurrent writers can remove a packet_type structure\n(which is correctly freed after an RCU grace period) and clear pt->dev\nwithout an RCU grace period.\nDefine ptype_iter_state to carry a dev pointer along seq_net_private:\nstruct ptype_iter_state {\nstruct seq_net_privatep;\nstruct net_device*dev; // added in this patch\n};\nWe need to record the device pointer in ptype_get_idx() and\nptype_seq_next() so that ptype_seq_show() is safe against\nconcurrent pt->dev changes.\nWe also need to add full RCU protection in ptype_seq_next().\n(Missing READ_ONCE() when reading list.next values)\nMany thanks to Dong Chenchen for providing a repro." ],
  "statement" : "This is an RCU synchronization bug in /proc/net/ptype iteration, where ptype_seq_next() and ptype_seq_show() accessed shared state without proper RCU-safe reads. A local attacker or stress tool may trigger the race by reading /proc/net/ptype while packet type or device state changes concurrently, leading mainly to RCU stalls or denial of service.",
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "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" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-23255\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23255\nhttps://lore.kernel.org/linux-cve-announce/2026031817-CVE-2026-23255-fc51@gregkh/T" ],
  "name" : "CVE-2026-23255",
  "csaw" : false
}