{
  "threat_severity" : "Moderate",
  "public_date" : "2025-11-12T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: xen/events: Return -EEXIST for bound VIRQs",
    "id" : "2414489",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2414489"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-670",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxen/events: Return -EEXIST for bound VIRQs\nChange find_virq() to return -EEXIST when a VIRQ is bound to a\ndifferent CPU than the one passed in.  With that, remove the BUG_ON()\nfrom bind_virq_to_irq() to propogate the error upwards.\nSome VIRQs are per-cpu, but others are per-domain or global.  Those must\nbe bound to CPU0 and can then migrate elsewhere.  The lookup for\nper-domain and global will probably fail when migrated off CPU 0,\nespecially when the current CPU is tracked.  This now returns -EEXIST\ninstead of BUG_ON().\nA second call to bind a per-domain or global VIRQ is not expected, but\nmake it non-fatal to avoid trying to look up the irq, since we don't\nknow which per_cpu(virq_to_irq) it will be in." ],
  "statement" : "bind_virq_to_irq() used a BUG_ON(ret < 0) which could be triggered when a VIRQ was already bound to another CPU. The condition can legitimately happen for non-per-CPU VIRQs. This allowed a reachable kernel assertion and caused a fatal panic inside the Xen guest kernel.\nA local privileged kernel context (e.g., a driver or subsystem) calling bind_virq_to_irq() while a VIRQ is already assigned to a different CPU. A guest user can indirectly trigger this via timing and repeated binding operations.\nFor the CVSS the PR:L, because only privileged kernel paths can directly trigger the VIRQ binding logic, but a local user can indirectly cause it by interacting with subsystems that manage event channels.",
  "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" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "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-2025-40160\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40160\nhttps://lore.kernel.org/linux-cve-announce/2025111239-CVE-2025-40160-b13a@gregkh/T" ],
  "name" : "CVE-2025-40160",
  "csaw" : false
}