{"id":"CVE-2026-23124","revision":"14c9e2a87e404f71aafa103db307e74e","records":[{"revision":"14c9e2a87e404f71aafa103db307e74e","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-23124","aliases":[],"title":"ipv6: annotate data-race in ndisc_router_discovery()","description":"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->ra_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 < IPV6_MIN_MTU || mtu > skb->dev->mtu) 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 -> 0xe5400659","state":0,"publishedAt":"2026-02-14T15:09:54.043+00:00","modifiedAt":"2026-10-19T18:25:32.245+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/ndisc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"4630897eb1a039b5d7b737b8dc9521d9d4b568b5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"2619499169fb1c2ac4974b0f2d87767fb543582b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"fad8f4ff7928f4d52a062ffdcffa484989c79c47\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"2a2b9d25f801afecf2f83cacce98afa8fd73e3c9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"e3c1040252e598f7b4e33a42dc7c38519bc22428\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7\",\n                            \"lessThan\": \"9a063f96d87efc3a6cc667f8de096a3d38d74bb5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/ndisc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.199\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.162\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.122\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.68\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.8\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/4630897eb1a039b5d7b737b8dc9521d9d4b568b5","https://git.kernel.org/stable/c/2619499169fb1c2ac4974b0f2d87767fb543582b","https://git.kernel.org/stable/c/fad8f4ff7928f4d52a062ffdcffa484989c79c47","https://git.kernel.org/stable/c/2a2b9d25f801afecf2f83cacce98afa8fd73e3c9","https://git.kernel.org/stable/c/e3c1040252e598f7b4e33a42dc7c38519bc22428","https://git.kernel.org/stable/c/9a063f96d87efc3a6cc667f8de096a3d38d74bb5"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23124","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-23124","identifiers":["CVE-2026-23124"]},"retained":false,"historicalAffected":[]}],"coverage":[]}