{"cve":"CVE-2023-53843","nvd":{"published":"2025-12-09T16:17:24.613","modified":"2026-06-17T06:46:10.160","status":"Deferred","description":"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's easy to repro with YNL:\n\n$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \\\n         --do new \\\n\t --json '{\"upcall-pid\": 1, \"name\":\"my-dp\"}'\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n\n$ ip link show\n-65536: some-port0: <BROADCAST,MULTICAST> 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 '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\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: {'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'}\n\nAccept 0 since it used to be silently ignored.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/881faff9e548a7ddfb11595be7c1c649217d27db","https://git.kernel.org/stable/c/a552bfa16bab4ce901ee721346a28c4e483f4066","https://git.kernel.org/stable/c/c965a58376146dcfdda186819462e8eb3aadef3a"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2023-53843","score":0.00244,"percentile":0.15611,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}