CVE-2026-23124

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Source
https://cve.org/CVERecord?id=CVE-2026-23124
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23124.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-23124
Downstream
Published
2026-02-14T15:09:54.043Z
Modified
2026-05-18T05:59:43.761789531Z
Summary
ipv6: annotate data-race in ndisc_router_discovery()
Details

In the Linux kernel, the following vulnerability has been resolved:

ipv6: annotate data-race in ndiscrouterdiscovery()

syzbot found that ndiscrouterdiscovery() could read and write in6dev->ramtu without holding a lock [1]

This looks fine, IFLAINET6RA_MTU is best effort.

Add READONCE()/WRITEONCE() to document the race.

Note that we might also reject illegal MTU values (mtu < IPV6MINMTU || mtu > skb->dev->mtu) in a future patch.

[1] BUG: KCSAN: data-race in ndiscrouterdiscovery / ndiscrouterdiscovery

read to 0xffff888119809c20 of 4 bytes by task 25817 on cpu 1: ndiscrouterdiscovery+0x151d/0x1c90 net/ipv6/ndisc.c:1558 ndiscrcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6protocoldeliverrcu+0xb2a/0x10d0 net/ipv6/ip6input.c:438 ip6inputfinish+0xf0/0x1d0 net/ipv6/ip6input.c:489 NFHOOK include/linux/netfilter.h:318 [inline] ip6input+0x5e/0x140 net/ipv6/ip6input.c:500 ip6mcinput+0x27c/0x470 net/ipv6/ip6input.c:590 dstinput include/net/dst.h:474 [inline] ip6rcvfinish+0x336/0x340 net/ipv6/ip6_input.c:79 ...

write to 0xffff888119809c20 of 4 bytes by task 25816 on cpu 0: ndiscrouterdiscovery+0x155a/0x1c90 net/ipv6/ndisc.c:1559 ndiscrcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6protocoldeliverrcu+0xb2a/0x10d0 net/ipv6/ip6input.c:438 ip6inputfinish+0xf0/0x1d0 net/ipv6/ip6input.c:489 NFHOOK include/linux/netfilter.h:318 [inline] ip6input+0x5e/0x140 net/ipv6/ip6input.c:500 ip6mcinput+0x27c/0x470 net/ipv6/ip6input.c:590 dstinput include/net/dst.h:474 [inline] ip6rcvfinish+0x336/0x340 net/ipv6/ip6_input.c:79 ...

value changed: 0x00000000 -> 0xe5400659

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23124.json",
    "cna_assigner": "Linux"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7
Fixed
4630897eb1a039b5d7b737b8dc9521d9d4b568b5
Fixed
2619499169fb1c2ac4974b0f2d87767fb543582b
Fixed
fad8f4ff7928f4d52a062ffdcffa484989c79c47
Fixed
2a2b9d25f801afecf2f83cacce98afa8fd73e3c9
Fixed
e3c1040252e598f7b4e33a42dc7c38519bc22428
Fixed
9a063f96d87efc3a6cc667f8de096a3d38d74bb5

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23124.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.15.0
Fixed
5.15.199
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.162
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.122
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.68
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.8

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23124.json"