{"id":"CVE-2026-97974","title":"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…","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= bd11ff421d36abdb585b9104fa70057bf01b3110 < e7ff91f19c1aae039a4257fa86fe849afe185291","Linux >= bd11ff421d36abdb585b9104fa70057bf01b3110 < 1155234c2227cf36072a43e1e09119472ade7ca7","Linux >= bd11ff421d36abdb585b9104fa70057bf01b3110 < cdca92eddc025fdb90071be97738f7d55a65f8dd","Linux 6.16"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:25.310","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97974","references":[{"url":"https://git.kernel.org/stable/c/1155234c2227cf36072a43e1e09119472ade7ca7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cdca92eddc025fdb90071be97738f7d55a65f8dd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e7ff91f19c1aae039a4257fa86fe849afe185291","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.870Z","slug":"CVE-2026-97974","body":"## Overview\n\nIn 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\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}