{
  "threat_severity" : "Moderate",
  "public_date" : "2025-12-09T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net: openvswitch: reject negative ifindex",
    "id" : "2420327",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2420327"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.1",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-1284",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnet: openvswitch: reject negative ifindex\nRecent changes in net-next (commit 759ab1edb56c (\"net: store netdevs\nin an xarray\")) refactored the handling of pre-assigned ifindexes\nand let syzbot surface a latent problem in ovs. ovs does not validate\nifindex, making it possible to create netdev ports with negative\nifindex values. It's easy to repro with YNL:\n$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \\\n--do new \\\n--json '{\"upcall-pid\": 1, \"name\":\"my-dp\"}'\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n--do new \\\n--json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n$ ip link show\n-65536: some-port0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000\nlink/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff\n...\nValidate the inputs. Now the second command correctly returns:\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n--do new \\\n--json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\nlib.ynl.NlError: Netlink error: Numerical result out of range\nnl_len = 108 (92) nl_flags = 0x300 nl_type = 2\nerror: -34extack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\\x0c\\x00\\x02\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0c\\x00\\x03\\x00\\xff\\xff\\xff\\x7f\\x00\\x00\\x00\\x00\\x08\\x00\\x01\\x00\\x08\\x00\\x00\\x00'], 'bad-attr': '.ifindex'}\nAccept 0 since it used to be silently ignored." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-05-22T00:00:00Z",
    "advisory" : "RHSA-2024:3138",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-04-30T00:00:00Z",
    "advisory" : "RHSA-2024:2394",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-427.13.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-04-30T00:00:00Z",
    "advisory" : "RHSA-2024:2394",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-427.13.1.el9_4"
  } ],
  "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" : "Out of support scope",
    "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-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "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-2023-53843\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53843\nhttps://lore.kernel.org/linux-cve-announce/2025120958-CVE-2023-53843-195d@gregkh/T" ],
  "name" : "CVE-2023-53843",
  "csaw" : false
}