CVE-2025-39980 (GCVE-0-2025-39980)
Vulnerability from cvelistv5
Published
2025-10-15 07:56
Modified
2025-10-15 07:56
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
nexthop: Forbid FDB status change while nexthop is in a group
The kernel forbids the creation of non-FDB nexthop groups with FDB
nexthops:
# ip nexthop add id 1 via 192.0.2.1 fdb
# ip nexthop add id 2 group 1
Error: Non FDB nexthop group cannot have fdb nexthops.
And vice versa:
# ip nexthop add id 3 via 192.0.2.2 dev dummy1
# ip nexthop add id 4 group 3 fdb
Error: FDB nexthop group can only have fdb nexthops.
However, as long as no routes are pointing to a non-FDB nexthop group,
the kernel allows changing the type of a nexthop from FDB to non-FDB and
vice versa:
# ip nexthop add id 5 via 192.0.2.2 dev dummy1
# ip nexthop add id 6 group 5
# ip nexthop replace id 5 via 192.0.2.2 fdb
# echo $?
0
This configuration is invalid and can result in a NPD [1] since FDB
nexthops are not associated with a nexthop device:
# ip route add 198.51.100.1/32 nhid 6
# ping 198.51.100.1
Fix by preventing nexthop FDB status change while the nexthop is in a
group:
# ip nexthop add id 7 via 192.0.2.2 dev dummy1
# ip nexthop add id 8 group 7
# ip nexthop replace id 7 via 192.0.2.2 fdb
Error: Cannot change nexthop FDB status while in a group.
[1]
BUG: kernel NULL pointer dereference, address: 00000000000003c0
[...]
Oops: Oops: 0000 [#1] SMP
CPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:fib_lookup_good_nhc+0x1e/0x80
[...]
Call Trace:
<TASK>
fib_table_lookup+0x541/0x650
ip_route_output_key_hash_rcu+0x2ea/0x970
ip_route_output_key_hash+0x55/0x80
__ip4_datagram_connect+0x250/0x330
udp_connect+0x2b/0x60
__sys_connect+0x9c/0xd0
__x64_sys_connect+0x18/0x20
do_syscall_64+0xa4/0x2a0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 Version: 38428d68719c454d269cb03b776d8a4b0ad66111 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ipv4/nexthop.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"status": "affected",
"version": "38428d68719c454d269cb03b776d8a4b0ad66111",
"versionType": "git"
},
{
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},
{
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"versionType": "git"
},
{
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"status": "affected",
"version": "38428d68719c454d269cb03b776d8a4b0ad66111",
"versionType": "git"
},
{
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"versionType": "git"
},
{
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"status": "affected",
"version": "38428d68719c454d269cb03b776d8a4b0ad66111",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ipv4/nexthop.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.8"
},
{
"lessThan": "5.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.245",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.194",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.155",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.16.*",
"status": "unaffected",
"version": "6.16.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.245",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.194",
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.109",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.50",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.16.10",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.17",
"versionStartIncluding": "5.8",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: Forbid FDB status change while nexthop is in a group\n\nThe kernel forbids the creation of non-FDB nexthop groups with FDB\nnexthops:\n\n # ip nexthop add id 1 via 192.0.2.1 fdb\n # ip nexthop add id 2 group 1\n Error: Non FDB nexthop group cannot have fdb nexthops.\n\nAnd vice versa:\n\n # ip nexthop add id 3 via 192.0.2.2 dev dummy1\n # ip nexthop add id 4 group 3 fdb\n Error: FDB nexthop group can only have fdb nexthops.\n\nHowever, as long as no routes are pointing to a non-FDB nexthop group,\nthe kernel allows changing the type of a nexthop from FDB to non-FDB and\nvice versa:\n\n # ip nexthop add id 5 via 192.0.2.2 dev dummy1\n # ip nexthop add id 6 group 5\n # ip nexthop replace id 5 via 192.0.2.2 fdb\n # echo $?\n 0\n\nThis configuration is invalid and can result in a NPD [1] since FDB\nnexthops are not associated with a nexthop device:\n\n # ip route add 198.51.100.1/32 nhid 6\n # ping 198.51.100.1\n\nFix by preventing nexthop FDB status change while the nexthop is in a\ngroup:\n\n # ip nexthop add id 7 via 192.0.2.2 dev dummy1\n # ip nexthop add id 8 group 7\n # ip nexthop replace id 7 via 192.0.2.2 fdb\n Error: Cannot change nexthop FDB status while in a group.\n\n[1]\nBUG: kernel NULL pointer dereference, address: 00000000000003c0\n[...]\nOops: Oops: 0000 [#1] SMP\nCPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014\nRIP: 0010:fib_lookup_good_nhc+0x1e/0x80\n[...]\nCall Trace:\n \u003cTASK\u003e\n fib_table_lookup+0x541/0x650\n ip_route_output_key_hash_rcu+0x2ea/0x970\n ip_route_output_key_hash+0x55/0x80\n __ip4_datagram_connect+0x250/0x330\n udp_connect+0x2b/0x60\n __sys_connect+0x9c/0xd0\n __x64_sys_connect+0x18/0x20\n do_syscall_64+0xa4/0x2a0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"
}
],
"providerMetadata": {
"dateUpdated": "2025-10-15T07:56:00.275Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/e1e87ac0daacd51f522ecd1645cd76b5809303ed"
},
{
"url": "https://git.kernel.org/stable/c/0e7bfe7a268ccbd7859730c529161cafbf44637c"
},
{
"url": "https://git.kernel.org/stable/c/ec428fff792b7bd15b248dafca2e654b666b1304"
},
{
"url": "https://git.kernel.org/stable/c/24046d31f6f92220852d393d510b6062843e3fbd"
},
{
"url": "https://git.kernel.org/stable/c/f0e49fd13afe9dea7a09a1c9537fd00cea22badb"
},
{
"url": "https://git.kernel.org/stable/c/8dd4aa0122885f710930de135af2adc4ccc3238f"
},
{
"url": "https://git.kernel.org/stable/c/390b3a300d7872cef9588f003b204398be69ce08"
}
],
"title": "nexthop: Forbid FDB status change while nexthop is in a group",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-39980",
"datePublished": "2025-10-15T07:56:00.275Z",
"dateReserved": "2025-04-16T07:20:57.150Z",
"dateUpdated": "2025-10-15T07:56:00.275Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2025-39980\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-10-15T08:15:35.887\",\"lastModified\":\"2025-10-16T15:29:11.563\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnexthop: Forbid FDB status change while nexthop is in a group\\n\\nThe kernel forbids the creation of non-FDB nexthop groups with FDB\\nnexthops:\\n\\n # ip nexthop add id 1 via 192.0.2.1 fdb\\n # ip nexthop add id 2 group 1\\n Error: Non FDB nexthop group cannot have fdb nexthops.\\n\\nAnd vice versa:\\n\\n # ip nexthop add id 3 via 192.0.2.2 dev dummy1\\n # ip nexthop add id 4 group 3 fdb\\n Error: FDB nexthop group can only have fdb nexthops.\\n\\nHowever, as long as no routes are pointing to a non-FDB nexthop group,\\nthe kernel allows changing the type of a nexthop from FDB to non-FDB and\\nvice versa:\\n\\n # ip nexthop add id 5 via 192.0.2.2 dev dummy1\\n # ip nexthop add id 6 group 5\\n # ip nexthop replace id 5 via 192.0.2.2 fdb\\n # echo $?\\n 0\\n\\nThis configuration is invalid and can result in a NPD [1] since FDB\\nnexthops are not associated with a nexthop device:\\n\\n # ip route add 198.51.100.1/32 nhid 6\\n # ping 198.51.100.1\\n\\nFix by preventing nexthop FDB status change while the nexthop is in a\\ngroup:\\n\\n # ip nexthop add id 7 via 192.0.2.2 dev dummy1\\n # ip nexthop add id 8 group 7\\n # ip nexthop replace id 7 via 192.0.2.2 fdb\\n Error: Cannot change nexthop FDB status while in a group.\\n\\n[1]\\nBUG: kernel NULL pointer dereference, address: 00000000000003c0\\n[...]\\nOops: Oops: 0000 [#1] SMP\\nCPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary)\\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014\\nRIP: 0010:fib_lookup_good_nhc+0x1e/0x80\\n[...]\\nCall Trace:\\n \u003cTASK\u003e\\n fib_table_lookup+0x541/0x650\\n ip_route_output_key_hash_rcu+0x2ea/0x970\\n ip_route_output_key_hash+0x55/0x80\\n __ip4_datagram_connect+0x250/0x330\\n udp_connect+0x2b/0x60\\n __sys_connect+0x9c/0xd0\\n __x64_sys_connect+0x18/0x20\\n do_syscall_64+0xa4/0x2a0\\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0e7bfe7a268ccbd7859730c529161cafbf44637c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/24046d31f6f92220852d393d510b6062843e3fbd\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/390b3a300d7872cef9588f003b204398be69ce08\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8dd4aa0122885f710930de135af2adc4ccc3238f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e1e87ac0daacd51f522ecd1645cd76b5809303ed\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ec428fff792b7bd15b248dafca2e654b666b1304\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f0e49fd13afe9dea7a09a1c9537fd00cea22badb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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