{"id":"CVE-2026-93226","summary":"ipv6: use RCU iterator to dump route exceptions","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: use RCU iterator to dump route exceptions\n\nrt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over\nRCU-protected exception lists. The caller holds rcu_read_lock(), but does\nnot hold rt6_exception_lock, so rt6_insert_exception() can concurrently\nadd an entry with hlist_add_head_rcu().\n\nKCSAN reports this race (irrelevant details omitted):\n\n  ==================================================================\n  BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions\n\n  write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5:\n    rt6_insert_exception+0x3bb/0x760\n    __ip6_rt_update_pmtu+0x4fe/0x750\n    ip6_sk_update_pmtu+0x19a/0x3b0\n    udpv6_err+0x3ff/0x800\n    icmpv6_notify+0x1e1/0x440\n    icmpv6_rcv+0x8c0/0xab0\n    ip6_protocol_deliver_rcu+0x616/0x840\n    ip6_input_finish+0xb9/0x160\n    ...\n    entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14:\n    rt6_nh_dump_exceptions+0xb3/0x260\n    rt6_dump_route+0x53e/0x5f0\n    fib6_dump_node+0x6d/0xf0\n    fib6_walk_continue+0x290/0x2d0\n    fib6_dump_table+0x28d/0x360\n    inet6_dump_fib+0x37d/0x620\n    rtnl_dumpit+0x7b/0xd0\n    netlink_dump+0x3ae/0x7e0\n    ...\n    entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  4 locks held by dumper/549:\n    ...\n    #1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620\n    #2: (&tb-\u003etb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360\n    #3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0\n\n  value changed: 0xffff8a7c44e05700 -\u003e 0xffff8a7c45d60100\n\n  Reported by Kernel Concurrency Sanitizer on:\n  CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted\n  7.2.0-rc7-virtme #38 PREEMPT(lazy)\n  ...\n\nUse hlist_for_each_entry_rcu() to safely iterate over the exception list.","modified":"2026-09-26T03:48:38.747062548Z","published":"2026-09-24T15:28:55.977Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93226.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db"},{"type":"WEB","url":"https://git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93226.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93226"},{"type":"PACKAGE","url":"https://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":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9"},{"fixed":"dffbfb3117138e8e0e09d05f507bd36ca1f696e5"},{"fixed":"6bd3f94ed858f2d072627546b4cdf712b0f8ea88"},{"fixed":"9c6be625e1a7258e845d6193b3b6b084a00f8e9e"},{"fixed":"3665abc3d2ae8a78cb67f858e848481432ec75db"},{"fixed":"eda56ee17713f9dd834b922f7dbfa2e25fa6358c"},{"fixed":"a602cd128d17a793e12888edc8eda85821ede7e1"},{"fixed":"f6b1b15848fd91fe122dac0d19d3d666e35075b6"},{"fixed":"47cdab0d51aaa9bd85f8e4904585bd5bd4df4488"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93226.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.3.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93226.json"}}],"schema_version":"1.9.0"}