CVE-2026-23304
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-03-25 11:16:26.180000
Last modified
2026-11-05 22:18:13.583000
View original CVE JSON
{
"id": "CVE-2026-23304",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-03-25T11:16:26.180",
"lastModified": "2026-11-05T22:18:13.583",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()\n\nl3mdev_master_dev_rcu() can return NULL when the slave device is being\nun-slaved from a VRF. All other callers deal with this, but we lost\nthe fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu()\nwith commit 4832c30d5458 (\"net: ipv6: put host and anycast routes on\ndevice with address\").\n\n KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]\n RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)\n Call Trace:\n ip6_pol_route (net/ipv6/route.c:2318)\n fib6_rule_lookup (net/ipv6/fib6_rules.c:115)\n ip6_route_output_flags (net/ipv6/route.c:2607)\n vrf_process_v6_outbound (drivers/net/vrf.c:437)\n\nI was tempted to rework the un-slaving code to clear the flag first\nand insert synchronize_rcu() before we remove the upper. But looks like\nthe explicit fallback to loopback_dev is an established pattern.\nAnd I guess avoiding the synchronize_rcu() is nice, too."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nipv6: corrección de desreferencia de puntero NULL en ip6_rt_get_dev_rcu()\n\nl3mdev_master_dev_rcu() puede devolver NULL cuando el dispositivo esclavo está siendo desasociado de un VRF. Todos los demás llamadores manejan esto, pero perdimos la alternativa a loopback en ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() con el commit 4832c30d5458 ('net: ipv6: put host and anycast routes on device with address').\n\n KASAN: desreferencia de puntero nulo en el rango [0x0000000000000108-0x000000000000010f]\n RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)\n Traza de Llamadas:\n ip6_pol_route (net/ipv6/route.c:2318)\n fib6_rule_lookup (net/ipv6/fib6_rules.c:115)\n ip6_route_output_flags (net/ipv6/route.c:2607)\n vrf_process_v6_outbound (drivers/net/vrf.c:437)\n\nMe sentí tentado a reelaborar el código de desasociación para borrar la bandera primero e insertar synchronize_rcu() antes de que eliminemos el superior. Pero parece que la alternativa explícita a loopback_dev es un patrón establecido. Y supongo que evitar el synchronize_rcu() también es bueno."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ipv6/route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "d542e2ac7f9e288d49735be0775611547ca4e0ee",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "a73fe9f4ae84a239d5b2686f47a58c158aee2eb4",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "4a48fe59f29f673a3d042d679f26629a9c3e29d4",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "581800298313c9fd75e94985e6d37d21b7e35d34",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "3310fc11fc47387d1dd4759b0bc961643ea11c7f",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "0b5a7826020706057cc5a9d9009e667027f221ee",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "ae88c8256547b63980770a9ea7be73a15900d27e",
"versionType": "git",
"status": "affected"
},
{
"version": "4832c30d5458387ff2533ff66fbde26ad8bb5a2d",
"lessThan": "2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/ipv6/route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.14",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.14",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.253",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.203",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.167",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.130",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.77",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.17",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.19.7",
"lessThanOrEqual": "6.19.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.0",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"affectedData": [
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.6",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.5",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.7",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.6",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.5",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.7",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.6",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.5",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.7",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.6",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.5",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.7",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem",
"defaultStatus": "unknown",
"versions": [
{
"version": "0",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.6",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.5",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Siemens",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"defaultStatus": "unknown",
"versions": [
{
"version": "V3.1.7",
"lessThan": "*",
"versionType": "custom",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-05T21:26:19.702592Z",
"id": "CVE-2026-23304",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.14",
"versionEndExcluding": "5.10.253",
"matchCriteriaId": "7144BCBC-124B-49FA-8BCC-259910F77E5A"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.11",
"versionEndExcluding": "5.15.203",
"matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.16",
"versionEndExcluding": "6.1.167",
"matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.2",
"versionEndExcluding": "6.6.130",
"matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.7",
"versionEndExcluding": "6.12.77",
"matchCriteriaId": "B3D12E00-E42D-4056-B354-BAD4903C03A5"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.13",
"versionEndExcluding": "6.18.17",
"matchCriteriaId": "A5E006E4-59C7-43C1-9231-62A72219F2BA"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "6.19.7",
"matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
"matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
"matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html",
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html",
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
]
}