CVE-2023-53843
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}'
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$ 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.
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.24%
- Percentil entre todas las CVEs puntuadas: 14
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2023-53843",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "54c4ef34c4b6f9720fded620e2893894f9f2c554",
"lessThan": "c965a58376146dcfdda186819462e8eb3aadef3a",
"versionType": "git"
},
{
"status": "affected",
"version": "54c4ef34c4b6f9720fded620e2893894f9f2c554",
"lessThan": "881faff9e548a7ddfb11595be7c1c649217d27db",
"versionType": "git"
},
{
"status": "affected",
"version": "54c4ef34c4b6f9720fded620e2893894f9f2c554",
"lessThan": "a552bfa16bab4ce901ee721346a28c4e483f4066",
"versionType": "git"
}
],
"programFiles": [
"net/openvswitch/datapath.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.47",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.4.12",
"versionType": "semver",
"lessThanOrEqual": "6.4.*"
},
{
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/datapath.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-09T16:17:24.613",
"references": [
{
"url": "https://git.kernel.org/stable/c/881faff9e548a7ddfb11595be7c1c649217d27db",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a552bfa16bab4ce901ee721346a28c4e483f4066",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c965a58376146dcfdda186819462e8eb3aadef3a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"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'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."
}
],
"lastModified": "2026-06-17T06:46:10.160",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}