{"id":"CVE-2026-98102","state":"PUBLISHED","title":"ipv6: mcast: fix RCU list diversion in ip6_mc_del1_src()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: fix RCU list diversion in ip6_mc_del1_src()\n\nWhen removing a source filter whose count reaches zero, ip6_mc_del1_src()\nunlinks psf from pmc->mca_sources. If the filter was previously active,\nthe code moved psf directly into pmc->mca_tomb by updating psf->sf_next.\n\nBecause pmc->mca_sources is traversed locklessly under RCU (e.g. by\nipv6_chk_mcast_addr()), mutating psf->sf_next before a grace period\nelapses diverts concurrent readers to the tombstone list. Consequently,\nreaders miss remaining active sources in pmc->mca_sources and improperly\nexamine deleted tombstone entries.\n\nFix this by allocating a new tombstone node for pmc->mca_tomb (as done\nin sf_setstate()) and retiring the original psf via kfree_rcu().","publishedAt":"2026-09-25T10:35:53.332Z","updatedAt":"2026-10-19T09:13:54.775Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"c3343cd7ec8706c221e52b782f386b9af14a928a","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"4352737297b262e8367675c19a7dc6a9f53c97af","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"8d4fe5c13f5056faa6deb09a90e24a89f9ebfad4","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"5149c60c406595b56fda0c6e9aae7fd287f636aa","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"93b49239840b91313adbd77b8b52993eff2d08c1","versionType":"git"},{"version":"86c49119f0353f857cc08030ec9e4ebaab3d5a64","status":"affected","versionType":"git"},{"version":"5.10.261","status":"affected","lessThan":"5.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/mcast.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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/mcast.c"]}],"references":["https://git.kernel.org/stable/c/c3343cd7ec8706c221e52b782f386b9af14a928a","https://git.kernel.org/stable/c/4352737297b262e8367675c19a7dc6a9f53c97af","https://git.kernel.org/stable/c/8d4fe5c13f5056faa6deb09a90e24a89f9ebfad4","https://git.kernel.org/stable/c/5149c60c406595b56fda0c6e9aae7fd287f636aa","https://git.kernel.org/stable/c/93b49239840b91313adbd77b8b52993eff2d08c1"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98102.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98102","state":"PUBLISHED","datePublished":"2026-09-25T10:35:53.332Z","dateUpdated":"2026-10-19T09:13:54.775Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.315Z"},"containers":{"cna":{"title":"ipv6: mcast: fix RCU list diversion in ip6_mc_del1_src()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: fix RCU list diversion in ip6_mc_del1_src()\n\nWhen removing a source filter whose count reaches zero, ip6_mc_del1_src()\nunlinks psf from pmc->mca_sources. If the filter was previously active,\nthe code moved psf directly into pmc->mca_tomb by updating psf->sf_next.\n\nBecause pmc->mca_sources is traversed locklessly under RCU (e.g. by\nipv6_chk_mcast_addr()), mutating psf->sf_next before a grace period\nelapses diverts concurrent readers to the tombstone list. Consequently,\nreaders miss remaining active sources in pmc->mca_sources and improperly\nexamine deleted tombstone entries.\n\nFix this by allocating a new tombstone node for pmc->mca_tomb (as done\nin sf_setstate()) and retiring the original psf via kfree_rcu()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"c3343cd7ec8706c221e52b782f386b9af14a928a","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"4352737297b262e8367675c19a7dc6a9f53c97af","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"8d4fe5c13f5056faa6deb09a90e24a89f9ebfad4","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"5149c60c406595b56fda0c6e9aae7fd287f636aa","versionType":"git"},{"version":"4b200e398953c237c86d32bf26d4cb2a96556a6f","status":"affected","lessThan":"93b49239840b91313adbd77b8b52993eff2d08c1","versionType":"git"},{"version":"86c49119f0353f857cc08030ec9e4ebaab3d5a64","status":"affected","versionType":"git"},{"version":"5.10.261","status":"affected","lessThan":"5.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/mcast.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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/mcast.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c3343cd7ec8706c221e52b782f386b9af14a928a"},{"url":"https://git.kernel.org/stable/c/4352737297b262e8367675c19a7dc6a9f53c97af"},{"url":"https://git.kernel.org/stable/c/8d4fe5c13f5056faa6deb09a90e24a89f9ebfad4"},{"url":"https://git.kernel.org/stable/c/5149c60c406595b56fda0c6e9aae7fd287f636aa"},{"url":"https://git.kernel.org/stable/c/93b49239840b91313adbd77b8b52993eff2d08c1"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:13:54.775Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.261"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}