{"api_version":"1","generated_at":"2026-09-27T14:16:36+00:00","cve":"CVE-2026-98103","urls":{"html":"https://cve.report/CVE-2026-98103","api":"https://cve.report/api/cve/CVE-2026-98103.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98103","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98103"},"summary":{"title":"igmp: convert struct ip_sf_list to RCU","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nigmp: convert struct ip_sf_list to RCU\n\nCommit 23d2b94043ca (\"igmp: Add ip_mc_list lock in ip_check_mc_rcu\")\nadded spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a\nuse-after-free while iterating im->sources during concurrent deletions.\n\nHowever, ip_check_mc_rcu() is called from RCU read-side critical\nsections in packet receive and route lookup fast paths (e.g.\n__mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()).\n\nWhen igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and\ncalls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(),\nan XFRM policy matching a multicast destination triggers\nxfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() ->\nip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock\nis already held on the same CPU, triggering a lockdep recursive locking\nwarning / deadlock.\n\nFix this by converting IPv4 struct ip_sf_list to RCU, mirroring the\nIPv6 implementation in net/ipv6/mcast.c:\n\n1. Add struct rcu_head to struct ip_sf_list and annotate sf_next,\n   sources, and tomb as __rcu pointers.\n2. Use rcu_assign_pointer() and kfree_rcu() for list updates and\n   deletions.\n3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse\n   im->sources locklessly with for_each_psf_rcu(), reading and writing\n   counter fields with READ_ONCE() and WRITE_ONCE().\n\nNote: RCU conversion of /proc/net/mcfilter will be done in a\nseparate patch.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:40","updated_at":"2026-09-25 11:17:40"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/f5182dfad54277267a8cb0c004a9cd4cf35aeebb","name":"https://git.kernel.org/stable/c/f5182dfad54277267a8cb0c004a9cd4cf35aeebb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e3206419bdb04e2087d8cc6be324df8639b3fac5","name":"https://git.kernel.org/stable/c/e3206419bdb04e2087d8cc6be324df8639b3fac5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d3011d1f293478c730aa0870490afa145c37600e","name":"https://git.kernel.org/stable/c/d3011d1f293478c730aa0870490afa145c37600e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2987ee196c88dbde0463dc87d5fb209c684e34a2","name":"https://git.kernel.org/stable/c/2987ee196c88dbde0463dc87d5fb209c684e34a2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98103","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98103","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 23d2b94043ca8835bd1e67749020e839f396a1c2 f5182dfad54277267a8cb0c004a9cd4cf35aeebb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 23d2b94043ca8835bd1e67749020e839f396a1c2 d3011d1f293478c730aa0870490afa145c37600e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 23d2b94043ca8835bd1e67749020e839f396a1c2 e3206419bdb04e2087d8cc6be324df8639b3fac5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 23d2b94043ca8835bd1e67749020e839f396a1c2 2987ee196c88dbde0463dc87d5fb209c684e34a2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b24065948ae6c48c9e20891f8cfe9850f1d748be git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e9924c4204ede999b0515fd31a370a1e27f676bc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 78967749984cf3614de346c90f3e259ff8272735 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4768973dffed4d0126854514335ed4fe87bec1ab git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d84708451d9041dff8a81e3718f821f12d2eb6c5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddd7e8b7b84836c584a284b98ca9bd7a348a0558 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 961447ff60291b91e27d5c32fa549c1411ad3b70 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d1a3c6d5925a8d00a32c5ef2d674dd9c0ce89c95 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.4.284 4.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.9.283 4.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.14.247 4.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.19.207 4.20 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.4.145 5.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.10.64 5.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.13.16 5.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.14.3 5.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* 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":{"cve_year":"2026","cve_id":"98103","cve":"CVE-2026-98103","epss":"0.001680000","percentile":"0.054050000","score_date":"2026-09-26","updated_at":"2026-09-27 00:04:19"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/linux/igmp.h","net/ipv4/igmp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f5182dfad54277267a8cb0c004a9cd4cf35aeebb","status":"affected","version":"23d2b94043ca8835bd1e67749020e839f396a1c2","versionType":"git"},{"lessThan":"d3011d1f293478c730aa0870490afa145c37600e","status":"affected","version":"23d2b94043ca8835bd1e67749020e839f396a1c2","versionType":"git"},{"lessThan":"e3206419bdb04e2087d8cc6be324df8639b3fac5","status":"affected","version":"23d2b94043ca8835bd1e67749020e839f396a1c2","versionType":"git"},{"lessThan":"2987ee196c88dbde0463dc87d5fb209c684e34a2","status":"affected","version":"23d2b94043ca8835bd1e67749020e839f396a1c2","versionType":"git"},{"status":"affected","version":"b24065948ae6c48c9e20891f8cfe9850f1d748be","versionType":"git"},{"status":"affected","version":"e9924c4204ede999b0515fd31a370a1e27f676bc","versionType":"git"},{"status":"affected","version":"78967749984cf3614de346c90f3e259ff8272735","versionType":"git"},{"status":"affected","version":"4768973dffed4d0126854514335ed4fe87bec1ab","versionType":"git"},{"status":"affected","version":"d84708451d9041dff8a81e3718f821f12d2eb6c5","versionType":"git"},{"status":"affected","version":"ddd7e8b7b84836c584a284b98ca9bd7a348a0558","versionType":"git"},{"status":"affected","version":"961447ff60291b91e27d5c32fa549c1411ad3b70","versionType":"git"},{"status":"affected","version":"d1a3c6d5925a8d00a32c5ef2d674dd9c0ce89c95","versionType":"git"},{"lessThan":"4.5","status":"affected","version":"4.4.284","versionType":"semver"},{"lessThan":"4.10","status":"affected","version":"4.9.283","versionType":"semver"},{"lessThan":"4.15","status":"affected","version":"4.14.247","versionType":"semver"},{"lessThan":"4.20","status":"affected","version":"4.19.207","versionType":"semver"},{"lessThan":"5.5","status":"affected","version":"5.4.145","versionType":"semver"},{"lessThan":"5.11","status":"affected","version":"5.10.64","versionType":"semver"},{"lessThan":"5.14","status":"affected","version":"5.13.16","versionType":"semver"},{"lessThan":"5.15","status":"affected","version":"5.14.3","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/igmp.h","net/ipv4/igmp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.15"},{"lessThan":"5.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","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":"6.12.111","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4.284","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9.283","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.247","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.207","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.145","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.64","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nigmp: convert struct ip_sf_list to RCU\n\nCommit 23d2b94043ca (\"igmp: Add ip_mc_list lock in ip_check_mc_rcu\")\nadded spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a\nuse-after-free while iterating im->sources during concurrent deletions.\n\nHowever, ip_check_mc_rcu() is called from RCU read-side critical\nsections in packet receive and route lookup fast paths (e.g.\n__mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()).\n\nWhen igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and\ncalls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(),\nan XFRM policy matching a multicast destination triggers\nxfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() ->\nip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock\nis already held on the same CPU, triggering a lockdep recursive locking\nwarning / deadlock.\n\nFix this by converting IPv4 struct ip_sf_list to RCU, mirroring the\nIPv6 implementation in net/ipv6/mcast.c:\n\n1. Add struct rcu_head to struct ip_sf_list and annotate sf_next,\n   sources, and tomb as __rcu pointers.\n2. Use rcu_assign_pointer() and kfree_rcu() for list updates and\n   deletions.\n3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse\n   im->sources locklessly with for_each_psf_rcu(), reading and writing\n   counter fields with READ_ONCE() and WRITE_ONCE().\n\nNote: RCU conversion of /proc/net/mcfilter will be done in a\nseparate patch."}],"providerMetadata":{"dateUpdated":"2026-09-25T10:35:53.942Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f5182dfad54277267a8cb0c004a9cd4cf35aeebb"},{"url":"https://git.kernel.org/stable/c/d3011d1f293478c730aa0870490afa145c37600e"},{"url":"https://git.kernel.org/stable/c/e3206419bdb04e2087d8cc6be324df8639b3fac5"},{"url":"https://git.kernel.org/stable/c/2987ee196c88dbde0463dc87d5fb209c684e34a2"}],"title":"igmp: convert struct ip_sf_list to RCU","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98103","datePublished":"2026-09-25T10:35:53.942Z","dateReserved":"2026-09-25T10:25:14.315Z","dateUpdated":"2026-09-25T10:35:53.942Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:40","lastModifiedDate":"2026-09-25 11:17:40","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98103","Ordinal":"1","Title":"igmp: convert struct ip_sf_list to RCU","CVE":"CVE-2026-98103","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98103","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nigmp: convert struct ip_sf_list to RCU\n\nCommit 23d2b94043ca (\"igmp: Add ip_mc_list lock in ip_check_mc_rcu\")\nadded spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a\nuse-after-free while iterating im->sources during concurrent deletions.\n\nHowever, ip_check_mc_rcu() is called from RCU read-side critical\nsections in packet receive and route lookup fast paths (e.g.\n__mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()).\n\nWhen igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and\ncalls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(),\nan XFRM policy matching a multicast destination triggers\nxfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() ->\nip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock\nis already held on the same CPU, triggering a lockdep recursive locking\nwarning / deadlock.\n\nFix this by converting IPv4 struct ip_sf_list to RCU, mirroring the\nIPv6 implementation in net/ipv6/mcast.c:\n\n1. Add struct rcu_head to struct ip_sf_list and annotate sf_next,\n   sources, and tomb as __rcu pointers.\n2. Use rcu_assign_pointer() and kfree_rcu() for list updates and\n   deletions.\n3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse\n   im->sources locklessly with for_each_psf_rcu(), reading and writing\n   counter fields with READ_ONCE() and WRITE_ONCE().\n\nNote: RCU conversion of /proc/net/mcfilter will be done in a\nseparate patch.","Type":"Description","Title":"igmp: convert struct ip_sf_list to RCU"}]}}}