{"cve":"CVE-2026-97974","nvd":{"published":"2026-09-25T11:17:25.310","modified":"2026-10-19T10:17:48.773","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: null-check fib6_node before accessing in __ip6_del_rt_siblings()\n\nsyzbot reported a null-ptr-deref in __ip6_del_rt_siblings() [0].\n\nThe stack trace hinted towards a null dereference of rt->fib6_node when\nfn->leaf is accessed in __ip6_del_rt_siblings(). With\nRTNL_FLAG_DOIT_UNLOCKED set, inet6_rtm_delroute() operations run\nconcurrently without acquiring the RTNL lock. In ip6_route_del(), the\nroute lookup happens under rcu_read_lock() without acquiring\ntable->tb6_lock.\n\nBetween ip6_route_del() looking up the route and __ip6_del_rt_siblings()\nacquiring table->tb6_lock, another thread can modify the routing table.\nFor example, when an ECMP route is replaced via RTM_NEWROUTE with\nNLM_F_REPLACE, fib6_add_rt2node() unlinks all old siblings and sets\niter->fib6_node = NULL. A reproducer was found that triggers this [1].\n\nAdd a check to ensure rt->fib6_node is non-null before accessing it.\n\n[0]\nKASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]\nRIP: 0010:__ip6_del_rt_siblings+0x31e/0x7c0 net/ipv6/route.c:4056\nCall Trace:\n <TASK>\n ip6_route_del+0x1054/0x1110 net/ipv6/route.c:4232\n inet6_rtm_delroute+0x5d7/0x6d0 net/ipv6/route.c:5669\n rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132\n netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556\n netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]\n netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345\n netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900\n sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800\n __sock_sendmsg net/socket.c:815 [inline]\n ____sys_sendmsg+0x565/0x870 net/socket.c:2713\n ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767\n __sys_sendmsg net/socket.c:2799 [inline]\n __do_sys_sendmsg net/socket.c:2804 [inline]\n __se_sys_sendmsg net/socket.c:2802 [inline]\n __x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2802\n do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]\n do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\n[1] https://gist.github.com/NamanGulati/0766a1159b6ca61928faaf87425ff899","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1155234c2227cf36072a43e1e09119472ade7ca7","https://git.kernel.org/stable/c/cdca92eddc025fdb90071be97738f7d55a65f8dd","https://git.kernel.org/stable/c/e7ff91f19c1aae039a4257fa86fe849afe185291"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-97974","score":0.00166,"percentile":0.05774,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}