{"id":"CVE-2026-93226","state":"PUBLISHED","title":"ipv6: use RCU iterator to dump route exceptions","description":"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->tb6_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 -> 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.","publishedAt":"2026-09-24T15:28:55.977Z","updatedAt":"2026-10-19T09:07:37.714Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"dffbfb3117138e8e0e09d05f507bd36ca1f696e5","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"6bd3f94ed858f2d072627546b4cdf712b0f8ea88","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"9c6be625e1a7258e845d6193b3b6b084a00f8e9e","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"3665abc3d2ae8a78cb67f858e848481432ec75db","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"eda56ee17713f9dd834b922f7dbfa2e25fa6358c","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"a602cd128d17a793e12888edc8eda85821ede7e1","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"f6b1b15848fd91fe122dac0d19d3d666e35075b6","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"47cdab0d51aaa9bd85f8e4904585bd5bd4df4488","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/route.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/route.c"]}],"references":["https://git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5","https://git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88","https://git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e","https://git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db","https://git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c","https://git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1","https://git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6","https://git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93226.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93226","state":"PUBLISHED","datePublished":"2026-09-24T15:28:55.977Z","dateUpdated":"2026-10-19T09:07:37.714Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T16:02:15.094Z"},"containers":{"cna":{"title":"ipv6: use RCU iterator to dump route exceptions","descriptions":[{"lang":"en","value":"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->tb6_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 -> 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"dffbfb3117138e8e0e09d05f507bd36ca1f696e5","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"6bd3f94ed858f2d072627546b4cdf712b0f8ea88","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"9c6be625e1a7258e845d6193b3b6b084a00f8e9e","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"3665abc3d2ae8a78cb67f858e848481432ec75db","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"eda56ee17713f9dd834b922f7dbfa2e25fa6358c","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"a602cd128d17a793e12888edc8eda85821ede7e1","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"f6b1b15848fd91fe122dac0d19d3d666e35075b6","versionType":"git"},{"version":"1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9","status":"affected","lessThan":"47cdab0d51aaa9bd85f8e4904585bd5bd4df4488","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/route.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/route.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5"},{"url":"https://git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88"},{"url":"https://git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e"},{"url":"https://git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db"},{"url":"https://git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c"},{"url":"https://git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1"},{"url":"https://git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6"},{"url":"https://git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:07:37.714Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}