{"id":"CVE-2026-97939","state":"PUBLISHED","title":"ipmr: account multicast table and route memory","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipmr: account multicast table and route memory\n\nA netadmin in a user+net namespace can create many IPv4 and IPv6\nmulticast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen\nid allocates an mr_table via the shared mr_table_alloc(), links it\ninto the per-net list, and leaves it until netns teardown. Those\nobjects were not charged to memcg, so the host unreclaimable slab\ngrows with the table count.\n\nAccount mr_table allocations with GFP_KERNEL_ACCOUNT and mark the\nIPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established\nhandling of IP addresses, routes and alternate interface names.\n\nUnresolved MFC entries are still allocated from softIRQ with\nGFP_ATOMIC and are not charged. They expire after 10 seconds and are\nbounded by the socket receive queue; see commit 0079ad8e8dc3\n(\"ipmr: remove hard code cache_resolve_queue_len limit\").","publishedAt":"2026-09-25T10:22:52.332Z","updatedAt":"2026-10-21T12:53:46.494Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"21e0749e8ef272ac7e3eefe0fa488a5983f4b038","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"ec1c6140394ee87127479bc500a3158b125bf07a","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"0264b3ee09b118fec8a5471b4ca288f8ab84722f","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"b7ee18725f2292ab554aa96a101ae42d45f008bd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/ipmr.c","net/ipv4/ipmr_base.c","net/ipv6/ip6mr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","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/ipv4/ipmr.c","net/ipv4/ipmr_base.c","net/ipv6/ip6mr.c"]}],"references":["https://git.kernel.org/stable/c/21e0749e8ef272ac7e3eefe0fa488a5983f4b038","https://git.kernel.org/stable/c/ec1c6140394ee87127479bc500a3158b125bf07a","https://git.kernel.org/stable/c/0264b3ee09b118fec8a5471b4ca288f8ab84722f","https://git.kernel.org/stable/c/d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c","https://git.kernel.org/stable/c/b7ee18725f2292ab554aa96a101ae42d45f008bd"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97939.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97939","state":"PUBLISHED","datePublished":"2026-09-25T10:22:52.332Z","dateUpdated":"2026-10-21T12:53:46.494Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:18:58.204Z"},"containers":{"cna":{"title":"ipmr: account multicast table and route memory","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipmr: account multicast table and route memory\n\nA netadmin in a user+net namespace can create many IPv4 and IPv6\nmulticast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen\nid allocates an mr_table via the shared mr_table_alloc(), links it\ninto the per-net list, and leaves it until netns teardown. Those\nobjects were not charged to memcg, so the host unreclaimable slab\ngrows with the table count.\n\nAccount mr_table allocations with GFP_KERNEL_ACCOUNT and mark the\nIPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established\nhandling of IP addresses, routes and alternate interface names.\n\nUnresolved MFC entries are still allocated from softIRQ with\nGFP_ATOMIC and are not charged. They expire after 10 seconds and are\nbounded by the socket receive queue; see commit 0079ad8e8dc3\n(\"ipmr: remove hard code cache_resolve_queue_len limit\")."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"21e0749e8ef272ac7e3eefe0fa488a5983f4b038","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"ec1c6140394ee87127479bc500a3158b125bf07a","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"0264b3ee09b118fec8a5471b4ca288f8ab84722f","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c","versionType":"git"},{"version":"f0ad0860d01e47a3ffd220564c5c653b3afbe962","status":"affected","lessThan":"b7ee18725f2292ab554aa96a101ae42d45f008bd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/ipmr.c","net/ipv4/ipmr_base.c","net/ipv6/ip6mr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","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/ipv4/ipmr.c","net/ipv4/ipmr_base.c","net/ipv6/ip6mr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/21e0749e8ef272ac7e3eefe0fa488a5983f4b038"},{"url":"https://git.kernel.org/stable/c/ec1c6140394ee87127479bc500a3158b125bf07a"},{"url":"https://git.kernel.org/stable/c/0264b3ee09b118fec8a5471b4ca288f8ab84722f"},{"url":"https://git.kernel.org/stable/c/d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c"},{"url":"https://git.kernel.org/stable/c/b7ee18725f2292ab554aa96a101ae42d45f008bd"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:53:46.494Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}