{"id":"AZL-77706","summary":"CVE-2026-23124 affecting package kernel for versions less than 6.6.126.1-1","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","modified":"2026-08-28T17:47:51.416361420Z","published":"2026-02-14T15:16:07Z","upstream":["CVE-2026-23124"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23124"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.126.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-77706.json"}}],"schema_version":"1.9.0"}