{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98103","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.315Z","datePublished":"2026-09-25T10:35:53.942Z","dateUpdated":"2026-09-25T10:35:53.942Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-25T10:35:53.942Z"},"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/igmp.h","net/ipv4/igmp.c"],"versions":[{"version":"23d2b94043ca8835bd1e67749020e839f396a1c2","lessThan":"f5182dfad54277267a8cb0c004a9cd4cf35aeebb","status":"affected","versionType":"git"},{"version":"23d2b94043ca8835bd1e67749020e839f396a1c2","lessThan":"d3011d1f293478c730aa0870490afa145c37600e","status":"affected","versionType":"git"},{"version":"23d2b94043ca8835bd1e67749020e839f396a1c2","lessThan":"e3206419bdb04e2087d8cc6be324df8639b3fac5","status":"affected","versionType":"git"},{"version":"23d2b94043ca8835bd1e67749020e839f396a1c2","lessThan":"2987ee196c88dbde0463dc87d5fb209c684e34a2","status":"affected","versionType":"git"},{"version":"b24065948ae6c48c9e20891f8cfe9850f1d748be","status":"affected","versionType":"git"},{"version":"e9924c4204ede999b0515fd31a370a1e27f676bc","status":"affected","versionType":"git"},{"version":"78967749984cf3614de346c90f3e259ff8272735","status":"affected","versionType":"git"},{"version":"4768973dffed4d0126854514335ed4fe87bec1ab","status":"affected","versionType":"git"},{"version":"d84708451d9041dff8a81e3718f821f12d2eb6c5","status":"affected","versionType":"git"},{"version":"ddd7e8b7b84836c584a284b98ca9bd7a348a0558","status":"affected","versionType":"git"},{"version":"961447ff60291b91e27d5c32fa549c1411ad3b70","status":"affected","versionType":"git"},{"version":"d1a3c6d5925a8d00a32c5ef2d674dd9c0ce89c95","status":"affected","versionType":"git"},{"version":"4.4.284","lessThan":"4.5","status":"affected","versionType":"semver"},{"version":"4.9.283","lessThan":"4.10","status":"affected","versionType":"semver"},{"version":"4.14.247","lessThan":"4.15","status":"affected","versionType":"semver"},{"version":"4.19.207","lessThan":"4.20","status":"affected","versionType":"semver"},{"version":"5.4.145","lessThan":"5.5","status":"affected","versionType":"semver"},{"version":"5.10.64","lessThan":"5.11","status":"affected","versionType":"semver"},{"version":"5.13.16","lessThan":"5.14","status":"affected","versionType":"semver"},{"version":"5.14.3","lessThan":"5.15","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/igmp.h","net/ipv4/igmp.c"],"versions":[{"version":"5.15","status":"affected"},{"version":"0","lessThan":"5.15","status":"unaffected","versionType":"semver"},{"version":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.3-rc2"},{"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"}]}]}],"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"}}}}