{
  "threat_severity" : "Moderate",
  "public_date" : "2025-05-02T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net_sched: hfsc: Fix a UAF vulnerability in class handling",
    "id" : "2363672",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2363672"
  },
  "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-416",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnet_sched: hfsc: Fix a UAF vulnerability in class handling\nThis patch fixes a Use-After-Free vulnerability in the HFSC qdisc class\nhandling. The issue occurs due to a time-of-check/time-of-use condition\nin hfsc_change_class() when working with certain child qdiscs like netem\nor codel.\nThe vulnerability works as follows:\n1. hfsc_change_class() checks if a class has packets (q.qlen != 0)\n2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g.,\ncodel, netem) might drop packets and empty the queue\n3. The code continues assuming the queue is still non-empty, adding\nthe class to vttree\n4. This breaks HFSC scheduler assumptions that only non-empty classes\nare in vttree\n5. Later, when the class is destroyed, this can lead to a Use-After-Free\nThe fix adds a second queue length check after qdisc_peek_len() to verify\nthe queue wasn't emptied." ],
  "statement" : "The bug could happen only when qdisc with child qdiscs like netem or codel being used.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-07-28T00:00:00Z",
    "advisory" : "RHSA-2025:11855",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.0",
    "package" : "kernel-0:6.12.0-55.24.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7 Extended Lifecycle Support",
    "release_date" : "2025-11-12T00:00:00Z",
    "advisory" : "RHSA-2025:21082",
    "cpe" : "cpe:/a:redhat:rhel_extras_rt_els:7",
    "package" : "kernel-rt-0:3.10.0-1160.142.1.rt56.1294.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7 Extended Lifecycle Support",
    "release_date" : "2025-11-12T00:00:00Z",
    "advisory" : "RHSA-2025:21063",
    "cpe" : "cpe:/o:redhat:rhel_els:7",
    "package" : "kernel-0:3.10.0-1160.142.1.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2025-09-29T00:00:00Z",
    "advisory" : "RHSA-2025:16920",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.77.1.rt7.418.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2025-09-29T00:00:00Z",
    "advisory" : "RHSA-2025:16919",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.77.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Advanced Update Support",
    "release_date" : "2025-11-18T00:00:00Z",
    "advisory" : "RHSA-2025:21667",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.2",
    "package" : "kernel-0:4.18.0-193.173.1.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
    "release_date" : "2025-12-04T00:00:00Z",
    "advisory" : "RHSA-2025:22752",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.4",
    "package" : "kernel-0:4.18.0-305.179.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On",
    "release_date" : "2025-12-04T00:00:00Z",
    "advisory" : "RHSA-2025:22752",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.4",
    "package" : "kernel-0:4.18.0-305.179.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
    "release_date" : "2025-10-29T00:00:00Z",
    "advisory" : "RHSA-2025:19222",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.166.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Telecommunications Update Service",
    "release_date" : "2025-10-29T00:00:00Z",
    "advisory" : "RHSA-2025:19222",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.6",
    "package" : "kernel-0:4.18.0-372.166.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions",
    "release_date" : "2025-10-29T00:00:00Z",
    "advisory" : "RHSA-2025:19222",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.6",
    "package" : "kernel-0:4.18.0-372.166.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "release_date" : "2025-10-22T00:00:00Z",
    "advisory" : "RHSA-2025:18932",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.8",
    "package" : "kernel-0:4.18.0-477.116.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "release_date" : "2025-10-22T00:00:00Z",
    "advisory" : "RHSA-2025:18932",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.8",
    "package" : "kernel-0:4.18.0-477.116.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-07-28T00:00:00Z",
    "advisory" : "RHSA-2025:11861",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.30.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-07-28T00:00:00Z",
    "advisory" : "RHSA-2025:11861",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.30.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
    "release_date" : "2025-08-19T00:00:00Z",
    "advisory" : "RHSA-2025:14054",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.0",
    "package" : "kernel-0:5.14.0-70.142.1.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
    "release_date" : "2025-08-19T00:00:00Z",
    "advisory" : "RHSA-2025:14094",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.0::nfv",
    "package" : "kernel-rt-0:5.14.0-70.142.1.rt21.214.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2025-08-13T00:00:00Z",
    "advisory" : "RHSA-2025:13781",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.130.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2025-08-11T00:00:00Z",
    "advisory" : "RHSA-2025:13633",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.130.1.rt14.415.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Extended Update Support",
    "release_date" : "2025-08-18T00:00:00Z",
    "advisory" : "RHSA-2025:13946",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.4",
    "package" : "kernel-0:5.14.0-427.83.1.el9_4"
  } ],
  "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 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-37797\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37797\nhttps://lore.kernel.org/linux-cve-announce/2025050210-CVE-2025-37797-2aab@gregkh/T" ],
  "name" : "CVE-2025-37797",
  "mitigation" : {
    "value" : "To mitigate this issue, prevent module sch_hfsc from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.",
    "lang" : "en:us"
  },
  "csaw" : false
}