{"api_version":"1","generated_at":"2026-09-26T13:26:54+00:00","cve":"CVE-2026-98099","urls":{"html":"https://cve.report/CVE-2026-98099","api":"https://cve.report/api/cve/CVE-2026-98099.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98099","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98099"},"summary":{"title":"ipv6: mcast: use rcu_assign_pointer() for __rcu list updates","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: use rcu_assign_pointer() for __rcu list updates\n\nSeveral places in net/ipv6/mcast.c update RCU-protected lists\n(np->ipv6_mc_list, idev->mc_list, idev->mc_tomb) using direct pointer\nassignments instead of rcu_assign_pointer():\n\n1. In __ipv6_dev_mc_dec(), unlinking a group from idev->mc_list did:\n       *map = ma->next;\n   without rcu_assign_pointer() while concurrent readers traverse\n   idev->mc_list locklessly under rcu_read_lock().\n2. In ipv6_sock_mc_drop() and __ipv6_sock_mc_close(), unlinking a group\n   from np->ipv6_mc_list directly assigned *lnk = mc_lst->next and\n   np->ipv6_mc_list = mc_lst->next without rcu_assign_pointer(), racing\n   with lockless readers in inet6_mc_check().\n3. In __ipv6_sock_mc_join(), mc_lst->next was initialized to\n   np->ipv6_mc_list via raw assignment before publishing mc_lst.\n4. In mld_del_delrec() and __ipv6_dev_mc_inc(), __rcu source pointers\n   passed into rcu_assign_pointer() lacked explicit dereference helpers.\n\nFix these by consistently using rcu_assign_pointer() along with\nmc_dereference() / sock_dereference().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:39","updated_at":"2026-09-25 11:17:39"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0c8f56c583c3250408367880c98e4d6fbc929315","name":"https://git.kernel.org/stable/c/0c8f56c583c3250408367880c98e4d6fbc929315","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6","name":"https://git.kernel.org/stable/c/2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98099","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98099","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 456b61bca8ee324ab6c18b065e632c9a8c88aa39 2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 456b61bca8ee324ab6c18b065e632c9a8c88aa39 0c8f56c583c3250408367880c98e4d6fbc929315 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.38","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.38 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv6/mcast.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6","status":"affected","version":"456b61bca8ee324ab6c18b065e632c9a8c88aa39","versionType":"git"},{"lessThan":"0c8f56c583c3250408367880c98e4d6fbc929315","status":"affected","version":"456b61bca8ee324ab6c18b065e632c9a8c88aa39","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv6/mcast.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.38"},{"lessThan":"2.6.38","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"2.6.38","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"2.6.38","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: use rcu_assign_pointer() for __rcu list updates\n\nSeveral places in net/ipv6/mcast.c update RCU-protected lists\n(np->ipv6_mc_list, idev->mc_list, idev->mc_tomb) using direct pointer\nassignments instead of rcu_assign_pointer():\n\n1. In __ipv6_dev_mc_dec(), unlinking a group from idev->mc_list did:\n       *map = ma->next;\n   without rcu_assign_pointer() while concurrent readers traverse\n   idev->mc_list locklessly under rcu_read_lock().\n2. In ipv6_sock_mc_drop() and __ipv6_sock_mc_close(), unlinking a group\n   from np->ipv6_mc_list directly assigned *lnk = mc_lst->next and\n   np->ipv6_mc_list = mc_lst->next without rcu_assign_pointer(), racing\n   with lockless readers in inet6_mc_check().\n3. In __ipv6_sock_mc_join(), mc_lst->next was initialized to\n   np->ipv6_mc_list via raw assignment before publishing mc_lst.\n4. In mld_del_delrec() and __ipv6_dev_mc_inc(), __rcu source pointers\n   passed into rcu_assign_pointer() lacked explicit dereference helpers.\n\nFix these by consistently using rcu_assign_pointer() along with\nmc_dereference() / sock_dereference()."}],"providerMetadata":{"dateUpdated":"2026-09-25T10:24:28.929Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6"},{"url":"https://git.kernel.org/stable/c/0c8f56c583c3250408367880c98e4d6fbc929315"}],"title":"ipv6: mcast: use rcu_assign_pointer() for __rcu list updates","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98099","datePublished":"2026-09-25T10:24:28.929Z","dateReserved":"2026-09-25T10:19:56.077Z","dateUpdated":"2026-09-25T10:24:28.929Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:39","lastModifiedDate":"2026-09-25 11:17:39","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98099","Ordinal":"1","Title":"ipv6: mcast: use rcu_assign_pointer() for __rcu list updates","CVE":"CVE-2026-98099","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98099","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: use rcu_assign_pointer() for __rcu list updates\n\nSeveral places in net/ipv6/mcast.c update RCU-protected lists\n(np->ipv6_mc_list, idev->mc_list, idev->mc_tomb) using direct pointer\nassignments instead of rcu_assign_pointer():\n\n1. In __ipv6_dev_mc_dec(), unlinking a group from idev->mc_list did:\n       *map = ma->next;\n   without rcu_assign_pointer() while concurrent readers traverse\n   idev->mc_list locklessly under rcu_read_lock().\n2. In ipv6_sock_mc_drop() and __ipv6_sock_mc_close(), unlinking a group\n   from np->ipv6_mc_list directly assigned *lnk = mc_lst->next and\n   np->ipv6_mc_list = mc_lst->next without rcu_assign_pointer(), racing\n   with lockless readers in inet6_mc_check().\n3. In __ipv6_sock_mc_join(), mc_lst->next was initialized to\n   np->ipv6_mc_list via raw assignment before publishing mc_lst.\n4. In mld_del_delrec() and __ipv6_dev_mc_inc(), __rcu source pointers\n   passed into rcu_assign_pointer() lacked explicit dereference helpers.\n\nFix these by consistently using rcu_assign_pointer() along with\nmc_dereference() / sock_dereference().","Type":"Description","Title":"ipv6: mcast: use rcu_assign_pointer() for __rcu list updates"}]}}}