{
  "threat_severity" : "Low",
  "public_date" : "2024-05-22T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm: khugepaged: skip huge page collapse for special files",
    "id" : "2282925",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2282925"
  },
  "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" : "verified"
  },
  "cwe" : "CWE-664",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm: khugepaged: skip huge page collapse for special files\nThe read-only THP for filesystems will collapse THP for files opened\nreadonly and mapped with VM_EXEC.  The intended usecase is to avoid TLB\nmisses for large text segments.  But it doesn't restrict the file types\nso a THP could be collapsed for a non-regular file, for example, block\ndevice, if it is opened readonly and mapped with EXEC permission.  This\nmay cause bugs, like [1] and [2].\nThis is definitely not the intended usecase, so just collapse THP for\nregular files in order to close the attack surface.\n[shy828301@gmail.com: fix vm_file check [3]]" ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-08-08T00:00:00Z",
    "advisory" : "RHSA-2024:5102",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.16.1.rt7.357.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-08-08T00:00:00Z",
    "advisory" : "RHSA-2024:5101",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.16.1.el8_10"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "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 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2021-47491\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47491\nhttps://lore.kernel.org/linux-cve-announce/2024052241-CVE-2021-47491-437d@gregkh/T" ],
  "name" : "CVE-2021-47491",
  "csaw" : false
}