{
  "threat_severity" : "Moderate",
  "public_date" : "2025-12-08T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm: hugetlb: fix UAF in hugetlb_handle_userfault",
    "id" : "2419847",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2419847"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-362",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm: hugetlb: fix UAF in hugetlb_handle_userfault\nThe vma_lock and hugetlb_fault_mutex are dropped before handling userfault\nand reacquire them again after handle_userfault(), but reacquire the\nvma_lock could lead to UAF[1,2] due to the following race,\nhugetlb_fault\nhugetlb_no_page\n/*unlock vma_lock */\nhugetlb_handle_userfault\nhandle_userfault\n/* unlock mm->mmap_lock*/\nvm_mmap_pgoff\ndo_mmap\nmmap_region\nmunmap_vma_range\n/* clean old vma */\n/* lock vma_lock again  <--- UAF */\n/* unlock vma_lock */\nSince the vma_lock will unlock immediately after\nhugetlb_handle_userfault(), let's drop the unneeded lock and unlock in\nhugetlb_handle_userfault() to fix the issue.\n[1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/\n[2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/" ],
  "statement" : "A race in the hugetlb + userfaultfd MISSING path could re-acquire locks after handle_userfault() while the target VMA might have been unmapped and freed, leading to a Use-After-Free and kernel crash (and possible exploitation).\nIf /proc/sys/vm/unprivileged_userfaultfd is set to 0 (disabled), the vulnerability cannot be triggered by unprivileged users, because creating a userfaultfd file descriptor then requires CAP_SYS_PTRACE or root privileges. As result the issue poses no risk in the default system configuration.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2023-11-07T00:00:00Z",
    "advisory" : "RHSA-2023:6583",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-362.8.1.el9_3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2023-11-07T00:00:00Z",
    "advisory" : "RHSA-2023:6583",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-362.8.1.el9_3"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Under investigation",
    "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" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "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-2022-50630\nhttps://nvd.nist.gov/vuln/detail/CVE-2022-50630\nhttps://lore.kernel.org/linux-cve-announce/2025120854-CVE-2022-50630-3891@gregkh/T" ],
  "name" : "CVE-2022-50630",
  "csaw" : false
}