GHSA-528J-V6CH-QQ32
Vulnerability from github – Published: 2026-02-14 15:32 – Updated: 2026-03-18 15:30In the Linux kernel, the following vulnerability has been resolved:
ipv6: annotate data-race in ndisc_router_discovery()
syzbot found that ndisc_router_discovery() could read and write in6_dev->ra_mtu without holding a lock [1]
This looks fine, IFLA_INET6_RA_MTU is best effort.
Add READ_ONCE()/WRITE_ONCE() to document the race.
Note that we might also reject illegal MTU values (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) in a future patch.
[1] BUG: KCSAN: data-race in ndisc_router_discovery / ndisc_router_discovery
read to 0xffff888119809c20 of 4 bytes by task 25817 on cpu 1: ndisc_router_discovery+0x151d/0x1c90 net/ipv6/ndisc.c:1558 ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438 ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500 ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590 dst_input include/net/dst.h:474 [inline] ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79 ...
write to 0xffff888119809c20 of 4 bytes by task 25816 on cpu 0: ndisc_router_discovery+0x155a/0x1c90 net/ipv6/ndisc.c:1559 ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438 ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500 ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590 dst_input include/net/dst.h:474 [inline] ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79 ...
value changed: 0x00000000 -> 0xe5400659
{
"affected": [],
"aliases": [
"CVE-2026-23124"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-14T15:16:07Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: annotate data-race in ndisc_router_discovery()\n\nsyzbot found that ndisc_router_discovery() could read and write\nin6_dev-\u003era_mtu without holding a lock [1]\n\nThis looks fine, IFLA_INET6_RA_MTU is best effort.\n\nAdd READ_ONCE()/WRITE_ONCE() to document the race.\n\nNote that we might also reject illegal MTU values\n(mtu \u003c IPV6_MIN_MTU || mtu \u003e skb-\u003edev-\u003emtu) in a future patch.\n\n[1]\nBUG: KCSAN: data-race in ndisc_router_discovery / ndisc_router_discovery\n\nread to 0xffff888119809c20 of 4 bytes by task 25817 on cpu 1:\n ndisc_router_discovery+0x151d/0x1c90 net/ipv6/ndisc.c:1558\n ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841\n icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989\n ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438\n ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489\n NF_HOOK include/linux/netfilter.h:318 [inline]\n ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500\n ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590\n dst_input include/net/dst.h:474 [inline]\n ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79\n...\n\nwrite to 0xffff888119809c20 of 4 bytes by task 25816 on cpu 0:\n ndisc_router_discovery+0x155a/0x1c90 net/ipv6/ndisc.c:1559\n ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841\n icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989\n ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438\n ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489\n NF_HOOK include/linux/netfilter.h:318 [inline]\n ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500\n ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590\n dst_input include/net/dst.h:474 [inline]\n ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79\n...\n\nvalue changed: 0x00000000 -\u003e 0xe5400659",
"id": "GHSA-528j-v6ch-qq32",
"modified": "2026-03-18T15:30:40Z",
"published": "2026-02-14T15:32:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23124"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2619499169fb1c2ac4974b0f2d87767fb543582b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2a2b9d25f801afecf2f83cacce98afa8fd73e3c9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4630897eb1a039b5d7b737b8dc9521d9d4b568b5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a063f96d87efc3a6cc667f8de096a3d38d74bb5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e3c1040252e598f7b4e33a42dc7c38519bc22428"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fad8f4ff7928f4d52a062ffdcffa484989c79c47"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
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.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- 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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
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.