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CVE-2023-53843 (GCVE-0-2023-53843)

Vulnerability from cvelistv5 – Published: 2025-12-09 01:30 – Updated: 2026-05-11 19:52
VLAI
Title
net: openvswitch: reject negative ifindex
Summary
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reject negative ifindex Recent changes in net-next (commit 759ab1edb56c ("net: store netdevs in an xarray")) refactored the handling of pre-assigned ifindexes and let syzbot surface a latent problem in ovs. ovs does not validate ifindex, making it possible to create netdev ports with negative ifindex values. It's easy to repro with YNL: $ ./cli.py --spec netlink/specs/ovs_datapath.yaml \ --do new \ --json '{"upcall-pid": 1, "name":"my-dp"}' $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' $ ip link show -65536: some-port0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff ... Validate the inputs. Now the second command correctly returns: $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' lib.ynl.NlError: Netlink error: Numerical result out of range nl_len = 108 (92) nl_flags = 0x300 nl_type = 2 error: -34 extack: {'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'} Accept 0 since it used to be silently ignored.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 54c4ef34c4b6f9720fded620e2893894f9f2c554 , < c965a58376146dcfdda186819462e8eb3aadef3a (git)
Affected: 54c4ef34c4b6f9720fded620e2893894f9f2c554 , < 881faff9e548a7ddfb11595be7c1c649217d27db (git)
Affected: 54c4ef34c4b6f9720fded620e2893894f9f2c554 , < a552bfa16bab4ce901ee721346a28c4e483f4066 (git)
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Linux Linux Affected: 6.1
Unaffected: 0 , < 6.1 (semver)
Unaffected: 6.1.47 , ≤ 6.1.* (semver)
Unaffected: 6.4.12 , ≤ 6.4.* (semver)
Unaffected: 6.5 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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      "affected": [
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          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/openvswitch/datapath.c"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: reject negative ifindex\n\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\u0027s easy to repro with YNL:\n\n$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \\\n         --do new \\\n\t --json \u0027{\"upcall-pid\": 1, \"name\":\"my-dp\"}\u0027\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json \u0027{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}\u0027\n\n$ ip link show\n-65536: some-port0: \u003cBROADCAST,MULTICAST\u003e mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000\n    link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff\n...\n\nValidate the inputs. Now the second command correctly returns:\n\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json \u0027{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}\u0027\n\nlib.ynl.NlError: Netlink error: Numerical result out of range\nnl_len = 108 (92) nl_flags = 0x300 nl_type = 2\n\terror: -34\textack: {\u0027msg\u0027: \u0027integer out of range\u0027, \u0027unknown\u0027: [[type:4 len:36] b\u0027\\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\u0027], \u0027bad-attr\u0027: \u0027.ifindex\u0027}\n\nAccept 0 since it used to be silently ignored."
        }
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        "dateUpdated": "2026-05-11T19:52:35.532Z",
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/881faff9e548a7ddfb11595be7c1c649217d27db"
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        {
          "url": "https://git.kernel.org/stable/c/a552bfa16bab4ce901ee721346a28c4e483f4066"
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      ],
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    "assignerShortName": "Linux",
    "cveId": "CVE-2023-53843",
    "datePublished": "2025-12-09T01:30:05.698Z",
    "dateReserved": "2025-12-09T01:27:17.826Z",
    "dateUpdated": "2026-05-11T19:52:35.532Z",
    "state": "PUBLISHED"
  },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-29T22:38:38+00:00",
      "cve": "CVE-2023-53843",
      "id": "CVE-2023-53843",
      "initial_release_date": "2023-01-01T00:00:00+00:00",
      "product_status:fixed": "399",
      "product_status:known_affected": "52",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: openvswitch: reject negative ifindex",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53843.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-02T01:41:53Z",
      "cve": "CVE-2023-53843",
      "id": "CVE-2023-53843",
      "initial_release_date": "2025-12-10T00:34:51Z",
      "product_status:known_affected": "394",
      "product_status:known_not_affected": "432",
      "product_status:recommended": "261",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2023-53843",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2023-53843.json",
      "version": "34"
    }
  }
}



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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.