{
  "threat_severity" : "Moderate",
  "public_date" : "2025-09-16T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare",
    "id" : "2395805",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2395805"
  },
  "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-125",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nefivarfs: Fix slab-out-of-bounds in efivarfs_d_compare\nObserved on kernel 6.6 (present on master as well):\nBUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0\nCall trace:\nkasan_check_range+0xe8/0x190\n__asan_loadN+0x1c/0x28\nmemcmp+0x98/0xd0\nefivarfs_d_compare+0x68/0xd8\n__d_lookup_rcu_op_compare+0x178/0x218\n__d_lookup_rcu+0x1f8/0x228\nd_alloc_parallel+0x150/0x648\nlookup_open.isra.0+0x5f0/0x8d0\nopen_last_lookups+0x264/0x828\npath_openat+0x130/0x3f8\ndo_filp_open+0x114/0x248\ndo_sys_openat2+0x340/0x3c0\n__arm64_sys_openat+0x120/0x1a0\nIf dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become\nnegative, leadings to oob. The issue can be triggered by parallel\nlookups using invalid filename:\nT1T2\nlookup_open\n->lookup\nsimple_lookup\nd_add\n// invalid dentry is added to hash list\nlookup_open\nd_alloc_parallel\n__d_lookup_rcu\n__d_lookup_rcu_op_compare\nhlist_bl_for_each_entry_rcu\n// invalid dentry can be retrieved\n->d_compare\nefivarfs_d_compare\n// oob\nFix it by checking 'guid' before cmp.", "A slab-out-of-bounds exists in the linux kernel in efivarfs_d_compare, such that the issue can be triggered by parallel lookups using an invalid filename due to an incorrect memcmp function." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-10-20T00:00:00Z",
    "advisory" : "RHSA-2025:18318",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.0",
    "package" : "kernel-0:6.12.0-55.40.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-11-12T00:00:00Z",
    "advisory" : "RHSA-2025:21118",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.1",
    "package" : "kernel-0:6.12.0-124.9.1.el10_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7 Extended Lifecycle Support",
    "release_date" : "2026-03-03T00:00:00Z",
    "advisory" : "RHSA-2026:3634",
    "cpe" : "cpe:/a:redhat:rhel_extras_rt_els:7",
    "package" : "kernel-rt-0:3.10.0-1160.147.1.rt56.1299.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7 Extended Lifecycle Support",
    "release_date" : "2026-03-03T00:00:00Z",
    "advisory" : "RHSA-2026:3685",
    "cpe" : "cpe:/o:redhat:rhel_els:7",
    "package" : "kernel-0:3.10.0-1160.147.1.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2025-10-27T00:00:00Z",
    "advisory" : "RHSA-2025:19103",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.81.1.rt7.422.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2025-10-27T00:00:00Z",
    "advisory" : "RHSA-2025:19102",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.81.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Advanced Update Support",
    "release_date" : "2025-12-17T00:00:00Z",
    "advisory" : "RHSA-2025:23445",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.2",
    "package" : "kernel-0:4.18.0-193.178.1.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
    "release_date" : "2026-01-14T00:00:00Z",
    "advisory" : "RHSA-2026:0533",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.4",
    "package" : "kernel-0:4.18.0-305.183.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-01-14T00:00:00Z",
    "advisory" : "RHSA-2026:0533",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.4",
    "package" : "kernel-0:4.18.0-305.183.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
    "release_date" : "2026-02-11T00:00:00Z",
    "advisory" : "RHSA-2026:2490",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.179.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Telecommunications Update Service",
    "release_date" : "2026-02-11T00:00:00Z",
    "advisory" : "RHSA-2026:2490",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.6",
    "package" : "kernel-0:4.18.0-372.179.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions",
    "release_date" : "2026-02-11T00:00:00Z",
    "advisory" : "RHSA-2026:2490",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.6",
    "package" : "kernel-0:4.18.0-372.179.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22072",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.8",
    "package" : "kernel-0:4.18.0-477.120.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22072",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.8",
    "package" : "kernel-0:4.18.0-477.120.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-10-20T00:00:00Z",
    "advisory" : "RHSA-2025:18281",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.55.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-11-12T00:00:00Z",
    "advisory" : "RHSA-2025:21112",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-611.7.1.el9_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-10-20T00:00:00Z",
    "advisory" : "RHSA-2025:18281",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.55.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-11-12T00:00:00Z",
    "advisory" : "RHSA-2025:21112",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-611.7.1.el9_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22066",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.0",
    "package" : "kernel-0:5.14.0-70.155.1.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22087",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.0::nfv",
    "package" : "kernel-rt-0:5.14.0-70.155.1.rt21.227.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22095",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.148.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2025-11-25T00:00:00Z",
    "advisory" : "RHSA-2025:22124",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.148.1.rt14.433.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Extended Update Support",
    "release_date" : "2025-11-19T00:00:00Z",
    "advisory" : "RHSA-2025:21760",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.4",
    "package" : "kernel-0:5.14.0-427.100.1.el9_4"
  } ],
  "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 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-39817\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-39817\nhttps://lore.kernel.org/linux-cve-announce/2025091615-CVE-2025-39817-90b7@gregkh/T" ],
  "name" : "CVE-2025-39817",
  "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
}